Temporary Subforum Access -- Yeah, easy.
Group steal -- Hmmm... Not bad idea I guess, but then you'll have a few users constantly stealing until they've drained a user dry, then they'll move to the next target. Not the way I want websites to work, but maybe someone else can do this one.
Itemshop -- I'll be coding an integral RPG later, this will be part of that.
Long post cash -- Nice idea, I like it. I'll see what this will take to do though.