You have to loctite it, because the screws are getting loose in that cracking of handles, they can fly out and do alot of nasty things. You need only torxdriver and glue to it, on BMs mostly T8 for main screws and T6 for latch, its getting loose too. Loctite 242, 243 is ideal, it holds 1 year, and you can unscrew the screws easily. You simply unscrew the screws, put a little bit of loctite on them and screw them back up.
Oiling... It's to smoother twirling and not squeezing, just put oil between (liners and) handles and the pivots, i can recommend WD-40, that would be best bet, but all kinds of oil are catching dirt, so i clean it sometime.
These things am I using and all works fine.

PS: Sorry for too much "screw" words.
