Easily yes. But as mentioned before you go too far with coral, I'd foucs on the fish additions to. As you populate more and feed accordingly, things in the water could change.
Featherduster might be a good "water quality at a glance" tool. They seem to do well when the water is good IMO
. Yes. mushrooms and feather dusters are good.
What's the plan on fish? 2 or 3?
Also, actinics for 8 or 9 hrs, and whites one shorter. In other words - my actinincs on at 1pm. They stay on all day and the whites on at 2pm. Whites off at 10 and actininc off at 11.