If your interested in an alternate to rewriting, I've implemented systems using a single rule that goes to a PHP module to perform the rewrites and variable extractions in other software..
I personally think this "rewriting" fashion is invented by somebody which will be never known, and it actually doesn't work for anything good. It's just a fake. Search engines index content much more efficiently when these rules are not set. Additionally, having numbers-only in URLs (i.e. having "quick-URLs" mode for miniBB) means having really friendly and universal URLs. They absolutely work on my private forums.
So with your solution... I don't know what it is about, but whomever it may interest, is only our Community, so you may post everything here... it's not the question we're specially interested in.