I'm just responding to one of the first sentences in the OP and letting you know it's perfectly fine to adjust the master fader, as long as you're aware of what's going on with your gain staging.
Thanks for the reply Melodeath. The varying info confused me. I was thinking that I was supposed to be leaving the faders for everything at unity and never touch them.
Essentially, I should record DI guitar (or any track, for that matter) without any processing and as hot as I'd like as long as it's without ever clipping. Then after I have the recorded audio I can add all signal processing and then I can move the track's fader as necessary to get it to the right peak level.