I guess the sig size would have applied to me. ^^
Even though that one would have caught my last sig image I still agree.
As far as one-word posts I don't see why it's a problem. There are many instances where I will post "
" instead of "That was really cute!" or "That made me laugh!". I just like to be concise.
The unreadable posts drive me crazy! I don't know about treating them as spam though. There are just a lot of people who may be just learning the language, or speak it and are functionally illiterate(or sometimes willfully ignorant). But in either case I think it's fair to allow it and simply request clarification. This may help the original poster to learn more successful written communication skills.
As far as profanity goes. I like the FYOS rule. Make sure that what you post is something you wouldn't mind your fourteen-year-old sister reading. The forum doesn't have to be appropriate for babies. Making the board strictly g-rated would stifle a lot of valid discussions about werewolves, art, and current events. But I think it would probably be good to have a few words/topics that just do not need to be posted here.
I think the reason this board has enjoyed some level of success so far is that most people self-regulate their posts out of an understood respect for others. (though sometimes we have seen that fly out the window) I think that more rules and strict enforcement of them just leads to strife. I like the laissez-faire style of the board. Sure we need someone to step in when things get out of control, but for the most part I think we should let things work themselves out.
(Putting my psychology degree to work)
The reason that this board has relatively little conflict is because the moderators usually stay out of small skirmishes. If a person is threatened with suspension from the forums, that motivation is purely external and he has no motivation to be respectful when the mods are not looking. But if the mods simply ask everyone to be nice and do not often threaten punishment, he will provide his own internal motivation for obeying the rules even when unsupervised.