doesn't it have a protective clear coat on the outside?
Almost certainly not. Unless the frame was painted (some were), "bare Ti" means just that.
To the OP: Litespeed, who should know something about it, says regular grease is plenty for any fitting threaded into Ti. I've used anti-seize (Ni based) on bottom brackets because I happened to have it around but it isn't essential. I use Phil grease on the waterbottle cage bolts, rear derailleur bolt, seatpost, etc. The front derailleur clamp doesn't need anything between it and the frame.
The best way to keep bottom brackets quiet is to wrap a layer or two of plumber's teflon tape around the threads. It acts as a lubricant, anti-seize and silencer.