Just an idea, but i'd like to share some basic questions i ask myself before going in a pug
say hello. are people replying? silence is a bad sign. <-- most important
(25 man)
- shift click the LFM toon. is he from a (even remotely) known guild? if not, don't join.
- Ask "what do we need?". if no reply, leave
(Heroics)
- If you care about the loot, check the leader's guild.
- Check that the tank has at least 20k hp
- Does he look def capped? how's the gemming? Check the healer gear.
ask questions if anything is wrong
In any case, if the people are fun, go anyway, ofc, wiping can be a good laugh, too
I remember some cases where i did an instant /leave :
Tank in green dps set. (hi, are you wearing your tanking armor? yes? gl, cya)
on my DK, was asked "can you heal" (wtf?)
invited as "last spot healer", 2 rogues, one shaman and a hunter. (where's the tank? *silence*)
no taunts after a few pulls, or i get aggro after 1 strike several times....
moar?