A Royal Gramma can be pretty territorial in a 30. But both of those other fish should be able to hold their own. I don't know what a flame angel would be like as an early addition because that is the last fish I added to my 75 gallon tank. But as such, that fish, just went about his business munching on the rocks and exploring even with my yellow tang backing up at him.
When I did have the gramma in my 29 gallon set up, he did intimidate my oscellaris clown a bit...