Even though equipment is weighed only at bigger matches, I personally wouldn't shoot a rifle I knew for a fact was over the weight limit, even if it was only a local competition. I shoot with a couple folks that do that and if they ever actually managed to post winning scores, I'm sure there would be challenges because their rifles are way overweight. I would not be comfortable if I shot well in a match knowing my rig was over the limit, but that's just me.
As far as the scope mag range, only your eyes can really tell you whether 22X would be a limiting factor. I recently shot a .308 DTA SRS Covert in a local 300 yd Reduced Palma (F-TR) match just for fun. The only scope/mount I had for it was a NF 5.5-22x50 in a LaRue LT-158 mount. We shoot these matches with 12" Shoot-N-C targets pasted over the NRA scoring target so that the shooter can see their impacts because this particular range doesn't have pits/target frames. For my eyes, the 22X was definitely limiting as it was very difficult to determine where my bullet holes were in relation to the very faint X and 10 scoring rings. Had I been running at 32X (or higher), I probably would have made better (larger) corrections than I did and gotten a bit better score. However, your eyes ultimately will let you know how much mag you need.
Different regional and national matches can use different equipment to weight your rifle. Sometimes it's a beat up old postal scale, which may or may not be very accurate. Other times it might be an extremely expensive balance. You just never know, which is why it's a good idea to be sure you're a couple ounces under the weight limit.
If you're as close to making weight as you described, there are other things you can do to shed a few ounces when necessary. If you're running a DBM system, mags can weight upwards of a third of a lb in some cases (AICS .308 mags, for example). You can remove the mag and install a mag follower of some sort. I have a couple homemade mag followers cut out of a closed cell foam that weigh next to nothing that I cut to fit the mag well. They work perfectly, just drop a round on top, close the bolt, and you're GTG. The use of alloy rather than steel rings can save a bit of weight. I know individuals that have gone as far as drilling holes in their bipod legs or rifle stocks in order to make weight; however, I would personally try very hard to find another route before going to that extreme. Finally, the bipod itself is often a component where weights of different makes/models can vary widely. If you're using one of the heavier types, chances are good you can find something the performs very similar that's a little bit lighter.