#1
I have a Tune-o-Matic bridge on my Schecter, and one of the saddles is extremely hard to adjust, and I'm not sure why.
#2
Odds are it has been rusted a bit. Take it off, apart, and spray/clean it with wd-40. Make sure to wipe it down after really well as wd-40 will corrode given time.
#3
could be rusted or cross-threaded. cross threading occurs when the screw threads do not seat properly into their threaded hole, but get driven in anyways. if you remove the screw and it looks all mangled, its cross threaded. replace the screw and saddle if this is the case
#4
Quote by krehzeekid
could be rusted or cross-threaded. cross threading occurs when the screw threads do not seat properly into their threaded hole, but get driven in anyways. if you remove the screw and it looks all mangled, its cross threaded. replace the screw and saddle if this is the case

Ah, I see...near the screw head, there's a washer. Will it interfere with taking the screw out?
#5
couldn't answer that for you without having seen it. however, if it looks like the others, it shouldn't pose an issue