Hi fisheye, I'm a total trigger nut though by far not the most advanced.
I've never owned a clown trigger before (but have had Picosso & Nigers) they are surprisingly slow growing so you'll be OK size wise in the tank for a while. He will get too big for a 75 though and will need about a 125 to live comfortably.
My triggers in the past were fine for a while with inverts..."for a while" is the key words though. Eventually they get hungry and start to nip at the inverts and then munch! Keeping him well fed will only delay the inevitable. I've found my triggers liked to pick on inverts for fun, never eating just breaking them. Pretty much every invert & live coral will be heavily damaged if not killed by him eventually, an expensive snack will all they'll become...sorry to be the bearer of bad news on that one.
You might want to consider replicated corals...that's what I use and maybe set up a Refuge and get your inverts out of the big tank and into it.
P.S. Not to scare you, but be mindful of your fingers when he gets big. I know someone who had to get stitches from her nearly 1 foot long Clown Trigger's bite.