Removing some bbcode?

I'm wondering if its easy to remove bbcodes from the punbb software. i want to remove the image and hyperlink bbcodes but retaining the rest

also, its not possible to change the default text size using bbcode in a vanilla punbb installation is it? only color, underline, bold, italics right? mainly because i'd rather users of my board not have the ability to change text sizes

love punbb, keep up the great work!