What? You'd rather write <img src="address"> than just the BBcode? ..
What for?
The BBCode is in to make it easier for people to do that kind of stuff. Making it harder seems like a bit of a contradiction. And why not just use the BBCode? It does whatever you should need to do on a forum.
If you wanna use <table>, <body>, <title> codes and stuff like that in posts, I don't think that should be possible at all. You could probably break a thread with it, it sucks for security reasons and people would be able to basically just slap the code of entire html pages into their posts. I'm afraid to think of what spammers could do with such opportunities .. horrible idea.