Opinions on how many more fish I can add to my tank without it being overcrowded?

It has been a crazy yet fun experience but I finally set up my first SW tank. It's been running a long time now so I got my first batch of fish this past weekend after having green chromis in there as testers for the past month. Here are the specs and stock list I currently have:

300-gallon 6-ft. tank w/side overflow

wet/dry filter w/sock

protein skimmer

2 return pumps

2 36" Marineland Doublebrights

Stock list currently in the tank:

(3) 1.5-inch green chromis

3-inch niger trigger

5-inch unicorn tang

5-inch blue tang

8-inch naso tang

4-inch volitan lionfish

2-inch sailfin blenny

Do you guys think I can add a little bit more fish into my tank without it being overcrowded? The other fish that I would want are a Huma Trigger, Foxface, and a Imperator Angelfish. I would be done after these additions. I know everyone's opinions are different, so let me hear a couple.

Thanks for the replies guys. I understand the the chromis will probably eventually get eaten, either by the lionfish or when my trigger(s) get bigger. The chromis were just the tester fish for my tank to see if it was ready. I like them, but I wouldn't be heartbroken if they got eaten. I have had mixed reviews about keeping triggers with a lionfish. Some say it's okay, some say one will eventually kill the other. I'm just hoping that they'll get along in the long haul. Yes, I'm really excited to add some large angels. I think they'll look great in my tank. But I'm the type of person that likes raising fish from juvenile to adulthood and with the angels, they totally transform in shape and color so that's what I'm really excited for.