-Please elaborate more what you expect in regard to what the definition of "forum etiquette" is.
-Please remove the "proper spelling and grammar is encouraged". You are already going over the fact that unintelligible babble won't be tolerated later in the rules....and this particular edict sounds like it's coming from a school marm or anal retentive librarian. Which is a bit awkward if not embarrasing considering the type of hardcore user you seem to want to attract.
-Please elaborate on what constitutes "derailing with the purpose to harass a user". This sounds way too generic and broad based, and could be used/abused/interpreted willy nilly depending on the parties and any bias the staff may have in perception of the posts.
-Please elaborate on the meaning of "if we think you are just bringing the site down". This is THE most dangerous rule of all, and sounds way too subjective and open up to interpretation as I just stated above. Kind of how police use "disorderly conduct" as their catchall crutch when no other crime has really been committed, just kind of throwing something at the wall hoping to make anything stick.