Saltman - here are my thoughts about your stocklist.
naso tang - great fish, love mine. In due time they WILL outgrow your tank and you will need to upgrade (period). Also a very docile fish. Need to ensure this guy is eating very well when you put the new guys in.
yellow tang - never been a big fan of them as they tend to be very volitile. If they are whacky then you have an issue and they will abuse a lot of fish on your list.
flame angel - Cool fish, but does not fit with the aggressive fish you have listed. Your Large angel will abuse this little guy in small quarters
maroon clown - Tend to be VERY VERY VERY territorial and could be an issue when it is 5"
purple tang - Great color, but has the same issue as the yellow above
emperor angel - My favorite fish of all time. Very bold and will not take lightly to new comers. Your 150 will be fine till he gets to be around 9" (the size of mine) and you will have to get a bigger home. In small quarters he will nip at all your fish to show his dominance.
bluethroat trigger - Sweet fish, IMO - I would get a pair of these guys and scratch the Huma Huma
niger trigger - Mine is a sweetheart. IMO you need to get this guy last and it needs to be the smallest fish. This will also be the largest fish in the tank when fully grown (18")
huma trigger - cool fish, but tend to go postal eventually. I have seen them in home aquariums and in the wild the size of a rugby ball, and let me tell you, when they are hungary you dont want to be anywhere near them.
maybe a Volitan and/or sailfin tang or a couple butterflys? Love lions, but I think that the emperor would nip at it and there would be a dead emperor and dead lion. Salfin tang will fight with the yellow tang. Butterflys would be the best bet. You could add 2 pakistan or raccoon butterflys.
All in all, your 150 should suffice for a couple of years. After that with the fish that you have chosen you will be looking at needing a 300+.