Well, that stuff should be easy enough to introduce, i mean, heck, if you wanted you could literally integrate it into your board lol...
Not sure how the UBB handles captcha thouh, nor am I sure how to really tie into the MySQL handler (at the presant time) but would all be possibl...
Myself on mine I use freecap to handle that, i'd recommend doing the eternal pages addon so it uses the board look, then just doing your own mysql handling/captcha
