Def need some nass snails. There are awesome. They will eat anything as well. As soon as you start to feed they will all pop out of the sand to eat
Some clowns like to date a coral before they marry it and move in.
It could be low alkalinity. Can you check it? If that's not it then look at your other levels. Has your skimmer been running?
Here she is in the flowerpot lol I think the flowerpot hates it
Just watch how the coral reacts. I have heard that those sometimes don't like to be bothered and will retract. But if it doesn't mind that's cool
I kept a clown with a flowerpot for about two years before the coral got to big for my 30L. If it's healthy it'll be perfectly fine.
Transfer over everything but the flowerpot and the clown then let it grow as big as the whole 29g. Now that'd be a nice lil display tank since you've got a 90 to play with now lol.