Seems Like Cheating Is Getting Bad

I looked at the game against koskati. I don't see anything in that game to make me think he cheated. What happened was, in a winning endgame, you blundered a rook. I'm sorry to say that, but it's true: you would have won vs this "cheater" if you hadn't blundered a simple knight fork.

You also should stop calling people "borderline retarded" just because of their chess rating. I don't think chess rating even has a particularly noticeable correlation with IQ, and he may just not be a very serious player.

Semi-OT regarding "FIDE Rated Tournaments (OTBs)":
Can everyone enter FIDE rated tournaments?
How much are the fees or can you enter some tournaments for free?
What can you do, if you don't have any rating at all and never played in a tournament?
Are there some special tournaments for beginners or low rated players?
Besides FIDE rules: Are there any manuals or instructions, how to behave in an OTB tournament?

@Beeco76 I'll take a crack at those questions!

Q1: Yes, although many are invitational. It depends on the tournament.
Q2: Depends entirely on the tournament. I would guess most large opens with FIDE-rated sections are expensive (in US and Canada at least!). But some chess clubs have FIDE events that are cheaper.
Q3: You can enter a tournament. I don't know which country you live in, but at the very least your tournament should be rated by the chess federation of the country you live in. You can go to the website of your federation and see where they are hosting rated events, and if you really want a FIDE rating in addition to your national rating, you can see if they are having any FIDE-rated tournaments.
Q4: Yes, but it depends highly on the tournament. A lot of tournaments have multiple sections and you could enter the lowest section.
Q5: Well there are a few unwritten rules. I would say it's pretty disrespectful to play all the way until mate if you're down a rook or more (and you don't have compensation), and probably eating at the board is not a very good thing to do. You also have to notate your games, and know how to play OTB with a clock.

There are many reasons why player's cheat. I have read posts from players who admit to using an engine occasionally during games. They justify doing so by saying they are "blunder checking" ie playing their own moves until the engine shows them that the move they were planning hangs a knight.

Lichess is actually the first chess site that I have heard admit that they cannot stop it but they will try their best. They don't bullshit about how advanced their cheat detection software is and pay Nakamura to agree with them. It is the nature of the beast. Online play will never be cheat proof.

In saying that I don't think any of those games were very suspicious. You just blundered. Even against stockfish you should have won that Rook vs Knight endgame.