This!
So many "huge" guitar parts are really huge bass parts
Very true. Try to resist too much low end in the guitars and find some good mids. I would always record most guitars mono, which gives you the possibility to create more stereo in the mix. The exception is if I want a stereo chorus type effect like a clean JC120.
Getting the low end right in a mix is one of the hardest things to do. Finding a separate place for the kick and bass guitar is key to a powerful sound.