I was actually contemplating making a post like this. I can (grudgingly) deal with the 75x75 15kb avatar limit (though I think 100x100 25kb is more reasonable), but the 150 character limit in signatures -
including code? That's pretty extreme as it means I barely have enough room for what I already have.
I moderate forums on another gaming site that has some tight restrictions about signature size to reduce forum clutter so I completely understand things from that angle. I think a better solution to reducing forum clutter, however, is not a character limit but a total image size limit (ie. combined, all the images in a sig cannot be larger than 300x50) combined with a lines limit (ie. no more than 2 returns). These two restrictions keep images contained to a reasonable amount of space and prevent extra text from becoming more prominent and taking up more vertical space than an actual post. The restrictions also allow forum users a bit more freedom to be expressive, post links to their work or important info, and otherwise have some fun with their sigs.
Those are just my suggestions, of course. I obviously don't know exactly where you guys are coming from as far as the reasoning behind the current restrictions, so my solutions might be completely incompatible with what you have in mind.
