2. do a squish test. 2 main things. Get it set close to .055" and have the dome reshaped by a builder that knows his zillas. Squish tolerances will be a bit different depending on which builder you talk too. but, .055 is good middle ground. Adjust the squish clearance via base gasket. You can order different thicknesses from cometic.
I've been told and ran .050 on a average motor with a corrected dome. IMHO I'd go .050 to .055 but I wouldn't go any tighter than .050 unless you've got a fresh motor built by a knowledgeable builder.
2) Need better pictures of your dome, that one is waaay to close up and blurry
3) Do not remove the BB, those are plugs for different ports depending on the model of your carb.