Personal opinion: no.

It seems like they are accepting transactions whether it's non-standard or standard,
But other nodes by default will reject that transaction from you or their node as long as the locktime hasn't reached yet.
So the chance that it will reach a solo-miner/pool's node with non-default mempool setting is close to zero.

It'll just result with: "Locktime requirement not satisfied"

Remember the public key that you've pasted when you created the time locked address?
You need to provide the private key of that public key to be able to sign the raw transaction.

For the possible problem with the unsigned TX, it could be something in the coinb.in "transaction" page.
It's hard to tell without the raw tx.

Weird, it worked at my end (it's currently accepted by blockcypher).
I'm just waiting for the timelock to expire in order to re-broadcast it to other block explorers.

No, there will be no problem with the creation and signing of the RAW transaction regarding the timelock,
If it's still not past the timelock, you won't be able to broadcast it to most nodes (blockcypher's nodes will accept it though).

There must be a problem with the unsigned raw tx or the provided prv key if you're having problem with signing.

Is it non-testnet funds? Yes?

You just have to paste the redeem script above (New->Transaction) then click load (you need to be online).
Then all inputs should be displayed.

If you prefer "that" method, yes you can.

• Click Inputs tab, paste all of the required info, I guess you already know "Transaction ID" & "Amount".
• The "N" means tx input number, stating with 0 for the upper-most input.
• Script, your address' redeem script.
• in the Outputs tab, paste the receiver's address and the amount to send (the excess will be used as fee).

Proceed to Verify, Sign then Broadcast.

Note: coinb.in might not be using our local time, my tx wasn't accepted by some nodes.

---

-edit-
This thread mentioned that it uses UTC for the date/time selection UI.
That explains why it still wasn't propagated yet (it's 8AM UTC while I set the timelock to 3:20PM).
At least we now know that the script is working

After reading his reply, I have tried it using bitcoin testnet coins and I found out that coinb.in is also capable of signing transactions with CLTV.
That's quite expected since they offer creation of "Time Locked Address".

-edit: replaced using pooya's workaround-
TXID: 7aea29fc36e56b277ec23b31c792f0182f030bbef32bd39cb451f512ccb5e5a2

For testing coinb.in in testnet, you won't be able to create the raw transaction using "load" method, you need to manually add the txid, input number, script and amount.
You also won't be able to broadcast using the broadcast tab.
For mainnet, everything should work smoothly.

Don't sweat it, it's enough. There's no single instance of a bruteforced 12-word mnemonic.
And the passphrase is a huge security boost, because if ever your seed phrase got compromised, the hacker will only be able restore a different set of addresses unless he also knows your passphrase.

One solid evidence would be: showing Wallet A's master public key. But that involves showing all of your wallet's addresses and transactions.

By giving it to someone who knows Bitcoin, it will be possible to show that the change (UTXO) from that particular transaction was the one sent to WalletB because they were derived from the same SEED.
If the wallet isn't HD (Hierarchical Deterministic) or the used change address was just imported, this can't be used because anyone can just "import private key" to add the address to the wallet.

Providing the transaction ID alone isn't that solid IMO, it's too easy "fake" the change address by using "coin control" or "pay to many" option/command.

About that, he already managed to restore one of the address in a watch-only wallet and the balance is still there (in the OP).

I'm pretty sure it's either a wrong seed backup or the original 'legacy' wallet was created using the invalid checksum "BIP39 trick".
If it's the latter, the issue must be already solved by now.

Let me try to explain: In Bitcoin-qt, the client-part handles the "tagging" & those labels (tags) will be saved in the wallet.dat file not in the blk.dat files (blockchain).
In Blockchain(dot)com's case, those tags were saved in their website's database.

BTW, in blockcypher users can also add tags to addresses, but it's not authenticated by signed messages so anyone can write whatever they want.
Just like blockchain.com, it's not saved in the "blockchain".

Bitcoin Core doesn't have a SEED Phrase.
You can get the master private key from your dumpwallet file if your wallet is "HD", and yes, it will restore all of your address using a client that supports "master keys" if you've selected the correct derivation path.
Or get the keys using tools like iancoleman to get all of your private keys from it to be able to import to Bitcoin Core.

IMO, for Bitcoin Core, it's for the "last resort" in case your wallet.dat got corrupted.

It depends on your backup preferences.
Dumpwallet can be printed on one or more A4 size papers (for offline physical backup).
Backupwallet obviously can only be stored in a file storage device.
SEED? No, you can only backup the "extended private masterkey" (xprv) from your dumpwallet file but this wont restore the private keys that you've imported to the wallet.

2. Yes
1. Those that starts with "5, L or K" before the date and time are the private keys of the "addr=" in the same line.
I believe "reserve=1" was indicated because those aren't used yet or no label but Core initially loaded the wallet.dat with (1000?) key pairs.
Script should be your address(es)' Redeem script, if you have a P2SH-Segwit or imported P2SH addresses.

You're hodling hundreds of thousands worth of Bitcoins in a mobile device? You should be using a hardware wallet by now.
Anyways, how about your backup, is it safe from hackers or anyone close to you (physically)?
Copay is an HD wallet so one way to get hacked is through your SEED or backup.

Maybe not relevant, but someone just reported the same "hacking" issue to their github repo:Funds lost from wallet #10373
If it isn't your seed or device, they are the only one who can help you with this matter.

For your own protection, do not display your master public key (xpub) in the public
because all of your previous and future transactions/addresses will be visible once it was imported.

Yeah I'm pretty sure Bitcoin was hammered and torched before, but it's never been drilled.

For the version, there's an old topic in stack overflow (that you can google search) that received a couple of replies,
but the developer, Gavin Andresen didn't replied on-topic.
https://bitcoin.stackexchange.com/questions/705/why-hasnt-the-bitcoin-client-advanced-to-version-1-0

My personal opinion: Bitcoin is still in beta because of these (761 open issues: https://github.com/bitcoin/bitcoin/issues).

This usually happens when the base unit was set to mBTC which causes confusion for newbies;
You can set it into "BTC" by clicking "Tools->Preferences->General Tab->Base Unit".

Yes for bitcoin-qt (Bitcoin-cli doesn't have a GUI), but it's disabled by default; If not better, it's in par with other client's coin-control feature.

Electrum desktop can pretty much do everything you've mentioned here, including client-side freezing of UTXO and addresses.
To view your available UTXOs, click "view->Show Coins" then open "Coins" tab.
What you need to do is to freeze the specific UTXO (as a mark) because you currently can't label each individually.
For multiple selection, use CTRL+Left Click, then right click to select "spend from".

Okay, it looks like you're "sweeping" them to an existing wallet because "sweep" will create a transaction and requires valid inputs.
You need to create a new 'imported' wallet in order to "import" or provide the correct address type.
If you prefer sweep, make sure that the wallet where the funds are going is spendable (not watch-only).

I assume that you already got the right private keys and on the ElectronCash import steps.
For the imported wallet creation process, do this:

• Select File->New/Restore if you already have a wallet opened / or Type the desired name of your wallet if your're in the wallet selection screen.
• Select the 4th option "Import Bitcoin addresses or private keys".
• Paste them one per line and proceed on creating the wallet.

edit -the steps to display correct addresses was already suggested in the local thread-

That's from BitcoinABC client, what are your trying to do?
But based from that screenshot, you are trying to send your BCH using that client which doesn't belong to any of the steps I've mentioned above.

If it's about NeuroticFish's "move your Bitcoin" (send-all) suggestion, you obviously need to do this in your Bitcoin Core client.
BTC = Bitcoin: use Bitcoin Core Client | BCH = Bitcoin Cash: use Bitcoin ABC Client

BTW, are you sure that you have BCH in your wallet?

Probably, you haven't synced BitcoinABC client and/or just directly copied the "wallet.dat" from Bitcoin Core into the wallet directory of BitcoinABC.
If syncing the client didn't worked, you have to export the master private key (if there no xprv, each of the prv keys) and import it into another client.

Do the suggestion above (send your entire BTC balance to your other wallet) first; then,
Follow these steps to dump those keys in one go:
Quoting myself to save "finger miles".

If your wallet is encrypted, use walletpassphrase "your_passphrase" 300 (including the " ") before entering dumpwallet command.
In your case, instead of downloading Electrum, you should use Electron Cash instead (electroncash.org).

No! This is how it should be:

• 1. Create a super sarcastic topic.
• 2. ???
• 3. Profit.

It will work, see OP.
You've earned it though, because this is what's really happening in the Beginners' board.
.
There was an alternative method (but this opportunity had ended now):

• 1. Go to online art template sites
• 2. Type "Happy 10th Anniversary Bitcointalk"
• 3. Save and Download.
• 4. Post it here: 10th anniversary art contest
• 5. Profit.