Shaving the bridge reduces its mass which can (according to the experts) affect how well the bridge drives the top. I'd avoid doing that. It'll also do nothing to fix your bellying problem.
The first Guild I had with severe bellying issues was a 12-string. The saddle was tipping forward to such a degree that not only was the intonation way off, but the bridge, which remained flat, was lifting all the way to the back row of guitar pins. (You can't expect a flat surface to remain glued to one that is bowed.)
To cap it off, the bellying in back of the bridge caused reciprocal dipping in front of it, around the sound hole. The strings came straight out of the bridge pin holes and over the saddle with almost no break angle.
My luthier -- a former authorized Martin repair guy -- repaired it with what was then a relatively new device, or at least one I'd never heard of before: a JLD Bridge Doctor. I've since put them in several of my Guilds with bellying problems, and they've made all the difference in the world in every one, no exceptions. They flatten the top, both in front of and behind the bridge; they improve the intonation; and in some guitars they improve the sound. (I put one in a DV52 that I'd had for several years and was very familiar with. The improvement in sound was so pronounced I couldn't believe my ears and removed the BD to see if I was imagining it. The guitar, which was already lively, had greater clarity in the mid-range with the BD.)
There's been a lot of discussion, pro and con, here and on virtually every other acoustic guitar forum, on the merits of Bridge Doctors -- check the archives.
The traditional way of fixing a bellying problem is to remove the bridge-plate and install a new one. This is a costly and somewhat difficult repair and the danger is that the bowing may come back eventually, because the bridge plate is so much smaller than the area that wants to belly.
Some people complain that the Bridge Doctor provides "only a temporary fix." It's only temporary if you take it out. So long as it's in there, it does everything its proponents claim.
Best of all, they're cheap and easy to install.
Good luck!
Glenn