Concerning cheats, so far my local experience has been for the most part clean. I have had no more than four suspicions, of which I only reported three for walling. I am not talking of casual since it is always chaotic, there is no point in looking for cheaters there.
There are many new accounts that I believe are alt accounts of experienced players.
Given the bugs of the game, like the peekers advantage issue, it is a bit counterproductive to cheater detection. I don't think Valve is training VACnet at the moment anyway; there are no demos to sample and train reports on. A lot of bans which are happening now will be temp bans.
The game does feel better with every patch.