Discussing this, I will working it out. Please do not metion their player name, but you can say rated player 1800s, 2000s whatever you want to, I will checked it out in every under rated tournament.

False problem in my opinion

overrated players can't subscribe to a tournament restricted to lower ratings.

If they can register that's because they are in the right range at the moment of the registration

Sure, this will determine that a player rated i.e. 1490 registering for a <1500 tournament will be able to appear slightly overrated if he wins a few matches after the registration, expecially if that player is quite "new" on chess.com

this problem can't be avoided tho.

As long as i can see, in official tournaments (normally covering all the rating ranges), if someone registers for a <1600 and then gets over rating before the tournament beginning he will be automatically registered for the higher rated tournament. Still, even there, if someone gets over the rating after the tournament has started there's no way to avoid it.

A.

My first tounament would be an exaple of this as explain by al11an. You get bonus points for winning I was in the 1200 1400 chess.com quick KO(16th) and after seveal wins was rated 1603 but enter as a 1300. So yeah rating at time of tournament starts and moveup(down) is possible

Every one comes in rated at 1200. It takes several games to find ones true rating. In a tournament there are going to be players new to chess.com and under rated. We need to be aware of that fact when we enter.