I'm not fish police, but I will tell you what I know from everything I have read over the years.
The recommended minimum for a harlequin tusk is 125. Many say their fish is so active they wouldn't even go in a tank of that size.
If the lionfish is a volitans, which i assume it is, it needs a minimum of 120. Don't worry on that one. Russell's lions are slightly smaller, but act and look very similar. They require only 70 gallons. There are also many types of dward lion.
Foxface looks good. peaceful, but venomous and can hold its own.
Tangs are borderline, but kole tangs and bristletooth tangs are both good for a tang that size. you'll get opinions on both sides for a yellow tang.
there are lots of dwarf angels you could get (only one in a tank that size though) look at flame angels, cherub, and coral beauties. these are all popular.
75 Gallon Reef