First part of the question depends on what predators are in the tank and the second would be anything coral that creeps , crawls and attaches to glass
The tank will be a mixed reef with zoas, mushrooms, montis, stylos and euphyllia. I would eventually like to be able to keep a dragonet so that means pods need to have places to breed. I’m thinking bare bottom will be nice from a maintenance stand point but if it’s going to limit my livestock options and make things like zoas and leptos and encrusting montis invasive, sand may be the way to go.
As long as your not keeping anything sand dwelling, you really don’t need that much sand
zoas and mushrooms would be easy to contain or fragged off of glass. As for montis and lepto I wouldn't put those on or near the glass that is terrible to remove. I also believe a dragonet would get "blown" around to much without sand to be comfortable in a bare bottom tank with typical reef flow. Pod population could also be hindered without sand for multiple reasons. Ive never had a bare bottom tank so take what I say with a grain of salt. But ive had most of the things you listed and have had a lot of the corals you've mentioned on or close enough to attach themselves to glass.
True, but many (most?) reef safe wrasses don't need sand (all fairies).
