There is a big difference between bitcoin and shitcoins though. So you can't really compare the two cases. For example take both his tweets about both bitcoin and dogecoin for example.
Bitcoin price goes up and stays up
Dogecoin price goes up then drops down
It would be the same with any other shitcoin because hyping a shitcoin creates a pump and a pump is followed by a dump without an exception but hyping bitcoin leads to more adoption and price rises and real rises with real adoption never reverse back.

It is the same with FUD, the panic caused in bitcoin is temporary and any drop caused by FUD will reverse but a shitcoin that drops after a FUD can not recover.

Difficulty of buying bitcoin is not affected by its price, the amount you can buy with the same amount of money changes but it will be as difficult or as easy to buy bitcoin as before even at $200k!

That is a terrible advice. You should never invest what you can't afford to lose specially if you are a newcomer to bitcoin world and not yet familiar with how things work with bitcoin itself (such as how to use wallets, security, cold storage,...) or with the market (specifically the unpredictable short term high volatility).

This is the only good advice in your whole post.

This is another terrible advice, more so for beginners.

This is not the truth. In most case altcoins that get dumped will never recover to their previous prices ever, specially if the pump preceding the dump wasn't the first pump and if it was a big one.

That's true but I was mostly talking about him believing in the technology, maybe I shouldn't have mentioned the billions of dollars part.
You see Elon Musk is not the average Joe that entered bitcoin hoping to make money, he doesn't need money since he is one of the richest men alive. He also has shown interest in the technology and what bitcoin offers not just the monetary value. That is why it is hard to believe someone like him using such a terrible wallet service.

This is the definition of a "pump and dump" group which are actually very common in the altcoin market. In fact it is not at all hard to pump and dump majority of altcoins, depending on the size of the altcoin it requires a bigger and more experienced group. For example big altcoins such as ethereum have bigger pumpers that have millions at their disposal thanks to the 72 million premined coins they had but smaller altcoins with low volume could be pumped by anyone with very small amount of money like 0.01BTC even.

You should start checking your words against the BIP39 word lists (found here, most probably only the English is needed) to make sure what you have has the possibility of being a valid mnemonic. This also helps if some words aren't in there (like 4 last ones) that may mean the first 12 are your mnemonic and the rest are your password.
Otherwise it may not even be one and as you guessed it could be some weird implementation with its own custom words. blockchain.com used to use a much longer word list with weird words in which case only their support can help you.

Bitcoin is more secure than both centralized and decentralized options.

The utility that bitcoin offers is a censorship resistance currency that can be used globally with a very fast speed. Other payment systems don't have any of that.

I don't think we can refer to this as a bug, it is more of a feature (with side effects). Besides users are not supposed to reveal their private keys in first place whether it is one or all.

The feature (meaning the way child keys are derived in a non-hardened path) allows something like what Electrum does, you create your mnemonic offline and derive the (public + private) keys there. Then only copy the master public key and move it to your online wallet and derive the same (public) keys there too.
Without this feature, this option wouldn't have been possible.

Right now we have psychological barriers that have to break otherwise the upward rise is not changing. But more importantly we have some traders that keep shorting bitcoin who are preventing the price from going up. These sudden rises that we have has been a good way of making them lose a lot of money. When they run out of money enough to discourage them from shorting bitcoin that is when the price would rise with more ease and reach $50k. It could take a couple of weeks though.

People keep saying Elon Musk and Tesla were the reason for the rise but it wasn't. It was just an excuse to punish these shorters. But now they are once again shorting bitcoin to make up for the money they just lost. They need another punushment.

I believe the main purpose of this "extra word/phrase" is to be able to create more than one wallet from a single mnemonic and add "plausible deniability" (not for security).
For example in case the user was forced to reveal their mnemonic or hand over their hardware wallet the device could produce a default wallet (without the extra word) that is either empty or has a small amount to fool the thieves while the same wallet with the extra word has the actual (bigger) balance.
This is also pointed out in BIP39

People who are in bitcoin to make money (more fiat) and would hate bitcoin if its price goes down are better hate bitcoin sooner than later and  then make their exit because they don't even know what bitcoin is and they don't care about it at all. Instead they care about fiat and want more of it.

Bitcoin won't be destroyed if its price dropped, even if the drop was significant. However bitcoin will be damaged the more idiot users it has who only care about their fiat profit!

What you are pointing out has nothing to do with bitcoin because bitcoin or more precisely bitcoin miners are simply consumers of the electricity not the producers of it. How electricity is produced (renewable energies, less polluting methods, ...) is up to the electric companies.

As long as you also warn people that Coinomi is a 100% closed source wallet that has been acting shady in the past and we don't know what they do to the users' mnemonics and other information even today.

That's just because Electrum has far more users than any other wallet, so there are a lot more targets.

This may not be the best idea. It is always better to separate wallets of each person and hopefully on a separate device. One mistake made by one person would mean a big loss for everyone. For example if one of them updated the wallet to a malicious one by mistake you would all lose your bitcoins.

That's the problem with using a library to brute force, they are not designed to be the most efficient. They are just optimized to perform one operation in reasonable time. From a quick look this part is being repeated pointlessly and it has obvious expensive processes such as the memory lookup even if it is a binary search, the conversion between the words and bits, working with strings, unnecessary checks,...
https://github.com/trezor/python-mnemonic/blob/master/mnemonic/mnemonic.py#L126-L156

What you want to do is to first convert all your words to their binary representation without having any memory issues.
13 file * 10 word each * 4 byte to hold bits = 520 byte total
Now you create the permutation of these bits and compute their hashes. Working with integers is significantly faster than working with strings.

Having a high cost to perform a certain type of attack doesn't mean the system is inefficient.

That is your assumption and can only happen if the bitcoin price drops significantly and stays low. Something like dropping down to $500 and staying there in which case your other statement is also wrong because it would cost a lot less to acquire 51% of the total supply too:

Elon may be trolling them and may not even have any accounts with this company. It is hard to believe someone who claims to believe in bitcoin for such a long time is using some poorly created web wallet for his billion dollar worth of bitcoins!

It really doesn't do that.
PBKDF2 is already a very weak key derivation function by design and using a very low iteration count (2048 instead of 10 million) isn't going to slow anything down either. In fact under the hood you are just computing about 4k HMACSHA512, suffice it to say that your CPU can compute millions of SHA512 in a second.

What people refer to as "increases security" is the passphrase that is used in BIP39 which I always argue that it cannot be considered a true security measure again due to weakness of the used KDF and the fact that there is no minimum size set for the passphrase and users aren't known for using strong passwords.

What's there to doubt?!
Have you forgotten what happened last month? That's not ancient history
They started spreading FUD and manipulated newbie weak hands to eventually crash the price from $42000 all the way down to $28800. That is 31% drop in 13 days. I don't know of any better evidence than that which clearly proves there are still a lot of newbie weak hands who fall for FUD and sell their bitcoins cheap.

Yes. Change addresses are derived similarly as any other addresses from your mnemonic (seed phrase). There is a derivation path depending on your address types such as m/0'/0/0 that Electrum uses to get your main addresses and it changes the last index to 1 for change addresses meaning the path becomes m/0'/1/0 for the first change address.

Technically there is absolutely no difference between a change address and "main" addresses in your wallet. They are all similar addresses of the same type with private keys and all derived from the same seed. The only difference is their "category".

What do you mean by that? You think when price drops it is the "darkest days"? It is actually quite the opposite, for instance when price went down as low as $3k a couple of years ago it was the best day in bitcoin world because you could buy bitcoin at a MASSIVE discount.

Most? I don't think so. There is still a very small percentage of the world that have accepted bitcoin.
Cryptocurrency? Not at all. They only see bitcoin and some investors may take a look at altcoins.