When I play scales, particularly the 4 octave ones, my sight tends to concentrate on the treble clef (my right hand) and I don't really look at the bass clef (left hand). Should I try to look at both treble and bass notes when practicing scales and arpeggios and not read only the right hand and let the left follow from memory.
I'm a little confused by what you wrote. When I practice 4 octave scales and arpeggios with both hands, I do tend to keep my eye on one hand or the other. It's good to switch that up, or don't look at your hands at all, just to keep you on your toes. I tend to watch my left hand while I play Chopin even though the right hand is doing everything.. Just a weird habit of mine I guess. But I digress.. But the way you wrote that, you kept mentioning the staffs, are you reading scales from a staff while you practice them? I'm not sure how useful that would be, you should be able to play scales and arpeggios w/o looking at any printed notes.
Also, would mentally saying each note in my head help as I play the scales.
If you can't look at a key and immediately know what note it is, or see a note and immediately know what key it is, then yes, this could be helpful. With practice you won't need to do that anymore. When I practice my jazz chords, my ii-V7-I progressions and what not, I "sing" outloud the name of the chord as I play it, just helps cement it, not just the name of it, but the tonality as well. the more "senses" you can incorporate the better you'll retain it.
I really don't like to sight read, but I want to be a good musician and being a good sight reader is a very beneficial thing in my opinion
I would agree with your opinion. I'm not the best reader either, but it is a worthwhile pursuit. It will definitely help you learn new pieces faster if it doesn't take 30 seconds to translate each written note to a key.. In the end though you should strive to memorize any piece you hope to perform, but always practice site reading as well.