hmm, nevermind. I seem to have figured it all out, lol

Once I went into cable box settings and changed it to auto, it seems some channels display in 720p and others in 1080i which I guess is normal.

Zoom also seems to work properly now (at least on some channels)

I think I will leave the TV's "pic size" setting @ "Native", and on most channels the "normal" Aspect Ratio setting on the cable box seems to look perfect.

Sorry for this rambling thread of questions which I solved all on my own before anyone could reply.

Mods may feel free to delete this, lol.