1 female betta, she's almost 2 and has always seemed very docile...
I currently do a 50% change every 2 days and a 100% once a week
So can a snail even live in an unfiltered tank?
If I just got one mystery snail is there any chance of it breeding?
Would I need to do more water changes?
And would you consider getting one if you had my same tank setup?
Yes, they are known to come out of the water I have mine in a bowl at the minute because I have aggressive fish in their tank that I'm getting rid off and not once have they even emerged from the water but I have read stories where snails have crawled across a room and their owners have stood on them.
They require temps of 77-80, they pretty much are like bettas when it comes to heat, the higher the temp the better they thrive IMO, they can live in a filtered tank but as they are messy it would just mean work for you with water changes,etc
Mystery snails like us :p need a male and a female to breed but that said they could have copulated at the store or wherever they were before you had it and since the female can store her eggs for months you could wake up to eggs on the tank wall one morning but it is unlikely IMO
If I had your set-up I would probably get a snail yes but it would be easier with a filter since you have a betta in there already :)