Since we're talking about filtering shit players here's a decent nugget of advice if you're going to run a Vampire the Masquerade game. First fucking don't use it as a crucible, since it's the second highest lot of idiots, sex perverts, self-centered clowns, and flakes this side of DnD. What? Still needing a filter? You FOOL! But okay, let's go with some tricks if you are insane enough to use this as a filter for other games or just like STing or playing.
First? Reject anyone who asks to play Tremere as their first clan pick. Shit players are attracted to them due to the blood magic for many a reason. Power gaming due to the many paths, being too Harry Potter brained to pick something else, and more. Toreador and Ventrue are yellow flags, since while a lot of shit players do play them, they tend to also be baby's first vamp. Brujahs you need to read their backstory, since it's 50/50 on them being insufferable politispergs or power gaming. Consider them if they pick Nosferatu or Gangrel. Be wary of munchkinery if they pick Tzimisce or LaSombra.
Second ask for their mortal life backstory. If they mention an orphanage instantly reject them. They're cooked. High school peaking and wage whining are not instant failure but treat as a yellow to orange flag. Reject if it's longer than ten sentences or so.
If they only have played v5, that is a soft yellow flag, you can fix them pretty easily. You will need to fix them if they ask about clan Hecate, since that was a mistake of existence.
Also reject dual packages. My first chronicle was a nightmare because I did not make that move to my eternal dismay.