there is no address for P2PK scripts  and they are not exactly obsolete, they are just not common anymore otherwise it is standard and practically do the same thing without hashing as P2PKH.

i can not for the life of me understand what you are trying to say here.

we have a redeem script, a signature script (scriptsig) and a pubkey script (scriptpub).
the redeem script is the script you use to "lock" the coins up and only reveal its hash which would be placed in the pubkey script of the transaction output.
while spending that redeem script goes into the signature script as a data being pushed to the stack since signature scripts spending a P2SH output must be push-only. then there are optional other data pushes (like signatures in a multi sig scheme) that should be placed before redeem script inside signature script.

it is hash of "pubkey" not private key.

this is exactly what the new bitcoin address encoding known as bech32 introduced. there is a human readable part at the beginning of each address (yo see it as "bc" for bitcoin mainnet addresses followed by '1' or the separator) where any shitcoin that copies bitcoin can also use with its own name.
currently a couple of these copy shitcoins are using this encoding. for example bcash is using the "bitcoincash" hrp for its addresses.

when bitcoin started miners were receiving 50 bitcoins for every block they were finding and that was worth nothing at first ($0) and eventually after 4 years it reached about $100-$150 per block.
today the miners are getting paid 6.25 bitcoins for every block they find and that is worth $71000+
in other words the reward has already decreased 87.5% while the amount of money they are earning has increased 71000%.

as bitcoin continues growing, its price will continue rising. there is also a lot of improvement in mining hardware (AKA ASICs) where they become more efficient and less costly which means hashrate will grow even if price stayed the same.

unless the blockchain analysis code is written in a naive way, they don't follow addresses but instead follow "coins" aka the "transaction outputs" which means it doesn't matter if your output script is one of the standard ones (that has an equivalent address) or a non-standard one.

all of this imagine this and imagine that, we don't have to imagine anything for ripple since it is already 100% centralized and they have also already reversed transactions. the rest of the nonsense regarding bitcoin mining and hashrate being "centralized in China" is an old FUD that has been spread for years starting from 2013 (maybe more). there is just no point in repeating the same responds over and over!

specially because of the current situation in the world this time the rise is going to be a lot bigger than all the times before. you see the governments have been printing money nonstop due to the pandemic and the economy crashing. that has started the devaluation of fiat specially the US dollar which may not be palpable right this moment but over time the effects of it will start showing up.
so even without adoption and the natural rise, the bitcoin value against USD and other fiat currencies will rise up because of that. now when you add the adoption on top of it, you can expect a much bigger rise.

as i've said before $400k to half a million for the next bubble peak is not going to surprise me.

the time and money that it costs to build something like that is not worth it in my opinion. i have done it myself a couple of years ago and kept the bot running for a moderately long time and i have to say the profit was not large enough to make it worthwhile specially since there is a big risk involved that has led to some losses during this strategy that eats through the small profit.

you could try and load the transaction directly by having the transaction ID of it or the raw bytes in hexadecimal format. all these options are found under Tools > Load transaction in your menu bar. for instance you could use the From text option and enter the raw tx hex (taken from blockchair.com)
and click broadcast.

there is a partial fix for this in BIP-147 that was deployed with SegWit soft-fork that forces this dummy value to be OP_0 whereas before it could be anything and waste more bytes.

that's correct. at protocol level there is no such thing as "address", there are only scripts that depending on the pubkey script they are evaluated in different ways and have to end up with a "true" at the end indicating success (with some other conditions which i skip for simplicity).
the "address" is just he human readable form of pointing to a handful of predefined scripts.

the main use case of stable coins such as Tether is for shitcoin trading and the more shitcoins that are created and traded the more stable coins must be printed to satisfy the need of altcoin pump and dumpers and the sheep that fall into their trap. there are currently nearly 10k shitcoins in existence with about 6.5k of them being actively traded on major exchanges with total volume of more than $100 billion on daily basis.

if you compare Tether total circulating supply of today with the number of shitcoins with the same numbers in another year like 2016 you can clearly see how the growth in number of shitcoins and the volume justifies the Tether supply.
you can also compare the total shitcoin volume versus Tether with total bitcoin volume versus Tether and also compare this last one with total bitcoin volume versus fiat and you can see that only 2 or 3 % of bitcoin volume is in Tether and the rest is in fiat whereas the rest is coming from shitcoin trades.

that's true you keep repeating the same bullshit on each cycle and just change the number. you did the same in 2015-2016 at the beginning of the bull run saying it is and i quote "confirmed fact that bitcoin will continue its historical down trend" while price was rising towards breaking the previous ATH and continuing to the new one, exactly like today.
you repeated the same thing in 2013, 2012,... and basically each time the rise is starting

it makes no sense to do something like this because you are still sending bitcoin on bitcoin blockchain to a bitcoin address but it is not impossible to implement considering the fact that we have 2 separate "wallets", a bitcoin wallet and an omni wallet.
so theoretically tether could introduce a different wallet encoding (or simply a different version byte) so that its addresses are rejected by the "bitcoin wallet" and the bitcoin addresses are rejected by the "omni wallet" while they both decode to the same scriptpub.

they are running a business so it is a smart move to advertise that business!

it is super easy with a 5 dollar wrench.


being around doesn't mean they also own bitcoin specially not large amounts. many buy small amounts, many lose their coins or spend them,...

i don't think so.
you see any coin that has a similar address as another one obviously had lazy developers who didn't care or even know about how to change a single line of code to produce a different looking address that is invalid by the wallet of the coin they are copying. so by definition that is a shitcoin and is useless. consequently it doesn't have any adoption let alone want to enter mass adoption.

there are exceptions like tether that don't have a network of their own and rely on bitcoin network. when you send tether you are actually sending them on bitcoin blockchain and to a bitcoin address so it makes sense that the address is the same.

why not? you see all the examples you mentioned or anything else that i can think of are changes that won't give any significant benefits or in almost all cases they decrease the security or add more weaknesses to bitcoin. for example PoS is significantly worse than PoW but if it were the other way around meaning if it were significantly better then i am certain that bitcoin would have changed already or risk being obsolete.

P.S. that Satoshi statement has not been true for many years since bitcoin has changed a lot of things. for example the script evaluation (which is a consensus critical matter) has changed with at least a dozen forks some involving scripts are BIP-16, 17, 34, 65, 112, 113 and 141.

https://live.blockcypher.com/btc/pushtx/
you will have to paste your entire tranasction hex (like what you posted in an earlier comment here) in this textbox and press broadcast.
keep in mind that there is no guarantee that other nodes would accept a transaction that may break one of their preferences (standard rules) such as RBF fee bump.

Lightning Network and Liquid are two very different networks though. while i have not seen any traces of centralization in LN so far i have seen some red flags indicating centralization in Liquid.
as for Tether, i believe they will start an LN network eventually like some other altcoins but it still has to be settled on bitcoin blockchain since unlike those coins USDT doesn't have its own separate blockchain or network.

well there are only a handful of countries out of nearly 200 that have actually banned or rejected bitcoin but when you look at the bigger picture many of the countries with very poor economy have not done that, some of them even accepted bitcoin like Venezuela for instance.
what you explained also may make sense in theory but in reality the volume is too low that it won't matter at all. for example in many of these poor-economy countries the total bitcoin trading volume (not just buying but both sell and buy) doesn't even reach $10k.

the stories i have seen were mainly about the scale of their operation not just about them selling bitcoin. these people that i've seen were basically running a business and making a lot of money by trading bitcoin on a daily basis and making a lot of money while not paying any taxes.
otherwise i have not yet seen anyone getting in trouble by buying/selling bitcoin P2P a couple of times.

to know more you must consult a lawyer who is familiar with your country's law specifically related to cryptocurrencies, running a small business and money laundry.