I would like to have 60A subpanle service wired for the basement.

Basement is unfinished and I would like to wire it prior to framing...

I am thinking of moving sumppump, creating new feed for sewrage pump,
service for new full bath, maybe move power for gas furnace to the
basement panel, plus 20 HALO lights in the future basement. ( Total
1700 sq ft)

My background is EE. So 110s and 240s, 360s don't phase me.

I have question about wiring.

0) My plan move some feeds from main to sub, install 60A double pole
breaker, run 2-2-4 to the pre-framed sub.
1) Do I run alu triplex like 2-2-4, or do I need quad? (Split neutra &
ground buses).
2) I was thinking of 60A service but now not sure if I should go with
100A.
3) When "fishing" am I required to take all drywall off and put metal
plates.
4) On vertical run to the panel how can I secure ( attach 2-2-4s) to
the studs ?

This is more of a learning project...