Yeah. I see your problem. I must admit that when I read your message, I kind of blanked on the fact that you were using web access rather than outlook. From what I can tell, people usually have to re-type their signature into owa emails. But, perhaps you could make a macro that opened a new message, did a carriage return or two, automatically added the signature & disclaimer and then returned the cursor to the home postion.
Like I said, I don't know anything about OWA so this is all speculation and perhaps not even an option. Good luck.