I need more advice on my engine build..

1. I have 452 ported heads milled .010 Combust cmber 86cc
2. I have selected the Comp cam Mag.460 230/230 480/480
3. I have selected roller rockers 1.75/1
4. I have a RPM Performer intake
5. I have selected a 750 Holly
6. I don't want to touch the lower end at this time.

My questions are..
1. Will I have enough clearance between the valves and
pistons with the heads milled .010 using this cam?
2. Can I take up to .050 total off the heads without
clearance problems? Is there any problems that arise from
removing this amount from the heads?
3 With using the thin Mopar head gasket and milling .050
removed from the heads, what will my compression be?
4 Is their anything else that can be done to increase the
compression without touching the lower end?