Are wrasses more peaceful or aggressive? I had, perhaps wrongly, assumed this was too small for a tang but I think that would be great if I can get away with it
No, you have enough room for most fairy and flasher wrasses and even a melanarus or yellow choris wrasse if you want one. They add a lively touch to most tanks. Avoid species like sixline wrasses (reported to be vicious by many) and red choris wrasses (they grow too big).
My first tip: try to acquire captive-bred or rehomed fish
only. They're typically much hardier than wild-caught specimens, and also less likely to be carriers for diseases. You should still quarantine, but I've found that it's been much safer to acquire my livestock from fellow reefers than from LFS. It's taken me a year to stock my tanks, but the wait's been worth it.
Banggai cardinalfishes just hang out in the water column, but don't provide much interest or kinetic energy in the tank.
Clownfish pairs can become aggressive and very territorial. I just bought some coral from an owner who was shutting down his tank: every time he put his hands in the tank, the ocellaris female started to bite his hands. No reef sharks for me, thanks!
The starry blenny and diamond goby are great choices, although the goby will cloud up your tank. I'd suggest adding more live rock to create a goby exclusion zone if you want sand off of any coral you put in the tank.
The coral beauty is a lovely fish -- and I'm sorry to say this -- but its colours are very Prime Prince: nothing but purple and gold all over the place. The flameback angel has a similar colour pallette but is much prettier, and will also probably leave your coral alone.
The pygmy whitespotted filefish is vastly underrated, and won't pick at your acans, unlike its unpredicatable cousin, the matted (aiptasia-eating) filefish.
You should probably avoid all dottybacks, but I still can't stop myself recommending -- with caution -- orchid dottybacks. They're unsurpassed for their fuchsia glory, and I've never had a problem with them. The caveat: I'd only buy them in (at least) pairs, and only captive-bred specimens. Many people have reported that they are devils when kept alone and/or when they have acquired wild-caught specimens.
