"is it ok" to use the individual track faders?
it is OK, no problem mate
tweaking the individual volumes of synths, samples is first to be done.
individual tracks faders leveling is to be done then, when you're into MIXDOWN of the track
any way of working is OK, but some tips are allways cool
just search for TAREKITH's GUIDES (to mastering, to leveling...) they are really good.
and have a lots of experimentation
getting red in the individual tracks may not be a really big problem, but you should avoid clipping in the master track, for sure.
cheers