Mandarin fish of any species aren't really suitable for a community tank.It would be hard to feed them,as they require livefoods,and I've yet to hear of one who will take frozen.Plus the tank should be established so that copepods have grown on the rocks.However,I've yet to try manadarin fish.
I would not house a mandarin in this size of tank, too small as i dont feel you would have enough live rock to get fully established with copepods..Scooter Blenny is NOT a blenny, is a dragonete and should be treated the same as the mandarin...so, a no no in my eyes..
Jawfish - Tank not suitable..would need 4 - 6 inches of mixed coarse and fine substrate for this fish to burrow safely.
No issues with the cleaner shrimp or watchman goby...
Starfish - No, unless you get a brittle star...which would still quite possibly need target feeding...If you chose brittle, saty away from the green star, very predatcious...
mandarians are not the best idea right now. Many say there fine in that small of a tank, but the more breeding ground for pods, the better, IE larger tanks, fuges and a lot of LR and macro algaes. Macro algaes in sumps provide massive breeding grounds for amphipods and copepods and other micro crustaceans, and is deffinantly going to be needed.