Hi all -- Site owner here. Clearly there's always going to be a push and pull between how many and what kind of ads cross the line versus getting the bills paid. (We ended up killing the full-page pop-over ads a few months back for this reason.)
With regard to the sticky bottom bar ads, for better or for worse (not sure who would argue for better), they've become a new standard over the last couple of years -- you see them on a lot of sites. We're working on tweaking them a bit so they don't immediately appear on every page load, but in the grand calculus of how to keep the site up and running, they may best be viewed as a necessary evil at this point.
We have considered offering a "premium" ad-free version of the site for those who'd like to support the forums and/or find the ads untenable. I'm dubious how many would actually be willing to fork out $10 a month, but that's a possible solution for offsetting the costs of hosting the forums.