Hmm,I would've thought you're living in the best place to get advice Lol.
I'll start the ball rolling to hopefully get more responses but must admit I've never grown an acer indoors.I don't think these plants are normally grown indoors unless you're gonna go down the bonsai route(of which I know nothing)They have the capablitiy to become a 10m tree and you will need to put it outside or at least a cold shed for the winter to induce dormancy(they need the rest)It may be possible to keep it indoors whilst small but even with pruning I think eventually it will be struggling for enough light(and space ha)
Anyway,yes put it in a pot,the roots don't want to be exposed to open air,mildy acidic-neutral free draining medium.If you have a sunnier window that may help with the lighting it'll need when it gets bigger.The temp. is fine.Snip those shrivelled leaves at the top of the leaf stalk,you may or may not get a new leaf grow there.As I said unless you're going to dwarf this plant it will grow a lot bigger so the wire may be a waste of time.
Sorry I can't help you more as it's unknown territory to me,but hopefully this'll spurn more replies...good luck!

I'll bet the people in the Bonsai Forum could help.

Here is a link that might be useful: Bonsai Forum

Thank you both for the responses. I hadn't planned on trying to bonsai it, but that may be a better option since I don't have any land to plant it in. I've moved it to the windowsill so it can get more light (though still no direct sunlight, and I'll get the materials to pot it ASAP! I don't know anything about potting soils, but I suppose I can just ask at the store for something with those qualities. To be honest my plant isn't doing that well (I think I was overwatering it as that bulb of moss doesn't drain well), but even if it dies I've enjoyed the experience enough to try again.

Now that I've noticed it, I've seen potted and planted Acers literally everywhere I go.

Thank you again for all your advice!

Well ya don't know 'til ya try...your little maple's got me thinking.I've got lots of new grafts so they cost me little and are dispensible lol,including my favourite 'Ukigomo'.In my view looks it's best grown in deep shade and grows very slowly here.So I'm going to put one on my window sill,SW facing.Normally too sunny an aspect for good colour but with the reduced light in the morning may turn out ok.I reckon there's enough light to sustain it until it's bigger than I'd want indoors,so I'm going to try and keep it small and see how it goes.It'll be nice to have a little maple indoors(albeit in the bathroom)even if only for a few years....we'll see.It'll be put outside come the autumn.

Here is a link that might be useful: