Yes. You can spend unconfirmed outputs.
Just note that you can't get confirmation for the child as long as the parent hasn't been confirmed. If the fee rate used for the child is equal or greater than the parent, both transactions will be included in the same block.


Yes, you can see many of them in the blockchain.

The private key of address A was probably compromised and the thief stole the fund. That's all. It could be due to the device being compromised or using a fake wallet.  
Note that miners can include both parent and child in the same block and there is no problem with that.

The thief saw the receiving transaction to the address A and made a transaction to address B while the transaction to address A was still unconfirmed.
The fee paid for these transactions was high enough and a miner included both of them in the same block.

Note that there are two different coinbase wallets. One of them is non-custodial and gives you a seed phrase and the other one is custodial.
I guess OP is referring to the non-custodial coinbase wallet here. If that's the case, he/she should be able to spend the fund once the receiving transaction gets one confirmation. It's also possible to import the wallet to electrum and spend the fund even when the receiving transaction is still unconfirmed.

It may worth mentioning that even their non-custodial wallet should be avoided. It's close source and there is no way to know how the keys are generated.

I mentioned Trezor, because it's surely one of the most popular hardware wallets. I didn't say Trezor is the best hardware wallet.
Visit the topic created by dkbit98 and see how the seed extraction vulnerability can cause users to lose their fund.
Trezor hacked (again)

For creating a watch-only wallet in electrum, you must import your address(es) or your master public key. There is no way to import a public key into electrum.
OP must import his/her addresses to create a watch-only wallet.

If you want the fund to be spendable, you can import your private keys instead of your addresses.

You can go for a good hardware wallet like Trezor. That's the best thing you can do. Visit the topic created by dkbit98 to know some other alternatives.
[LIST ] Open Source Hardware Wallets

If you can't afford to buy a hardware wallet or you don't want to use a hardware wallet for any other reason, you can use Unstoppable wallet. Visit the topic created by theymos.
Reminder: do not keep your money in online accounts

Since you referred to App Store, I guess you are looking for IOS version of electrum. If that's the case, note that electrum isn't available for IOS.
You can visit the official website and download electrum for Windows, macOS and Android.

Do not forget to verify your download. Below is the guide provided by DireWolfM14 on how to verify your download.
[GUIDE] How to Safely Download and Verify Electrum [Guide]

Not your keys, not your coins.
With keeping your bitcoin on an exchange, you give full control over your fund to a third party. Even if a centralized service has been around for a very long time, everything is still possible. They may go bankrupt or they may be hacked.


Trust wallet is close source and I would never recommend anyone to use it. We don't know how keys are generated on trustwallet.
There is no guarantee that what happened to Atomic wallet recently won't happen to trustwallet.

Electrum is a non-custodial wallet which means that it gives you full access to your private keys. Since electrum is open-source and its code has been reviewed by many people, you can be sure that it's secure enough.

Note that if you want your fund to be completely secure, you should run electrum on an airgapped device. Any online device is always prone to hacking.

Prediction 1: $30,200.00
bech32 address: bc1q06h9jgf2ccurtt0d07shkttjpdw5zdfkyh4l8j

OP's transaction is around 35 vMB from the tip and I don't think it will be confirmed in the next 2 days.

As already mentioned, OP's transaction hasn't been flagged as RBF and it's not possible to bump its fee.  
Using ViaBTC free accelerator is also impossible.


So, there is no way to use CPFP and you have to wait.

Your transaction hasn't been flagged as RBF and you can't bump its fee.
Since there is no change address in the transaction, you can use CPFP, only if you have full control over 1AZepsGtdPNoE369k6c8hMgWzVnkxQNbjd.

Where did you send the fund to? Does 1AZepsGtdPNoE369k6c8hMgWzVnkxQNbjd belong to a non-custodial wallet or a custodial service?
If the address belongs to a custodial service like an exchange, the only thing you can do is wait.

In the case a transaction hasn't been flagged as RBF, you can't bump its fee, even if you import your wallet into a wallet supporting RBF.


Viabtc doesn't rebroadcast transactions. If you submit your transaction to Viabtc, they will include it in the next block mined by them. That's different from rebroadcasting.
Note that for using ViaBTC free service, the fee rate must be equal or greater than 10 sat/byte. Otherwise, you have to use their paid service.


TO OP:
The image you shared doesn't help us know if your transaction has been flagged as RBF or you can use CPFP.
Can you share your transaction ID here? (Note that with sharing the transaction ID, you may harm your privacy.)

I would definitely prefer using electrum. Since iancoleman uses javascript, I would never recommend using that for generating a seed phrase.
To know why it's not a good idea to generate a seed phrase using javascript, click here and read gmaxwell's explanation.

The user hasn't been banned. It would be reported on BPIP if he\she had been banned.
According to loyce.club, the user had made 1 post which has been deleted by moderators.

It seems that the user has registered the account only for advertising purposes.

Electrum has been never compromised.
Electrum versions older than 3.3.4 had a vulnerability which allowed servers to display any arbitrary message. Some servers abused this feature and asked users to download a fake version of electrum. This was completely different from what happened to Atomic wallet users.
Electrum victims had downloaded a fake version while Atomic wallet victims downloaded a real version. Electrum victims made a mistake with downloading the application from a website other than the official website and not verifying GPG signatures.

With sending personal message to you (and probably some other users) and advertising his/her service, the user in question broke rule number 29.


Report the message you received to admins. He/she will be probably banned.

Trustwallet is close source and we don't know how exactly it's working.
I would always consider the worst-case scenario for any close source wallet and assume that developers have access to the keys, but we can't say that trustwallet developers definitely have control over users wallets.


A wallet can be close source and non-custodial.
Non-custodial means that users have access to the keys.

Take note that blockchain.com isn't a custodial wallet. Their wallet is non-custodial and gives users access to their private keys. Of course, I would never recommend anyone to use it.
OP's fund is now in blockchain.com exchange, not their wallet.

laszlo could make that transaction even without paying any transaction fee.

I just checked transactions included in blocks 56000-58000.
561 (non-coinbase) transactions were included in those blocks. 560 out of 561 transactions have been made with zero fee and laszlo's transaction was the only one paying fee.