I need suggestions, please.

[Skimmer Juice]

yes I was going to suggest a Halloween hermit as well. They are the best cleaners out there for algae on rocks IMO. I would also stay clear of the chromis , maybe look at some of the smaller blennys they have great personality . Had a few griesenger gobies a while back when I had a nano a little bit harder to find but one of the coolest fish out there. Or you could look for a panda gobie also not as common but would be perfect for a nano .