I think spoiler tags for the forum will be nice. With so many discussion about series and stuff, it's convenient to have spoiler tags around for mega plot spoilers. Not everybody enjoy reading what's the ending, and exactly who is the bad guy in the show. There's a choice of not reading certain stuff with spoiler tags around.
As for punctuations and grammar, I don't think it's that big a problem here in Spcnet, most of the posts here are coherent enough. Sure, sentences with no commas or caps or periods are annoying, but flamers and spammers are even worse.
Anyhow, I think clearing up the members' database is a good idea as well.