<snip>You do hear a lot of scare stories about applying anti seize to brake fasteners. One of the most often read ones is that applying anti seize to bolts can increase the required torque load, sometimes leading to stripped threads. How much of that is fact and how much mechanical urban internet myth I couldn't say.
Mostly myth. The tightening torque for a particular fastener - particularly the ones in the braking system - is a function of the fastener size, pitch and grade. They're probably Grade 8.8 or better fasteners. Here's a
handy-dandy chart from the Fastenal folks which has both wet and dry torque values. Even without Fastenal's 'wet' chart, you can simply reduce the the torque value by ~25-30% and be safe.
Still on braking systems, some of the torque values are specified by Subaru . . . but they really don't matter that much - you are simply clamping two things together in a non-critical way. Compare this to your cylinder head fasteners, which must compress a head gasket, form a liquid-tight seal, handle extreme expansion and contraction - all rather big deals. Your brakes get hot and cool off - otherwise you just care that they don't fall off.
I use anti-seize on just about everything and I recommend that to anyone - particularly if you live in a climate with occasional salt applications to the streets. Anti-seize is the same as a 'lubricated fastener' - the wet chart.
Either wet or dry, you should be nowhere near the yield value of the fastener, including stripping threads. If someone is stripping threads, he's not checking torques, his torque wrench is badly broken, he's using the wrong grade fastener, he (or someone) has cross-threaded that fastener at some earlier time or something similar.
I am a big fan of stainless fasteners generally. There's none of that holding of one's breath and praying that a rusted bolt isn't going to snap!!
Unless you're buying aircraft grade fasteners, you may find that stainless steel bolts are less forgiving than their carbon steel cousins. That said, many Ace Hardware stores carry a good selection of stainless metric cap screws, usually in 8.8 grade. They are in merchandiser trays stocked by the Hillman company. It's worth a look. Some of the Dorman merchandisers at auto parts stores also have stainless fasteners. Finally, if you have any tool & die suppliers in your area, give them a phone call. They might have what you need in a 'broken lot' so you can buy 2 or 4 cap screws or some other small quantity. Or, you could use anti-seize.
