I'm not sure repotting is the way to go either, it may invite more problems, jades are good in the same pot for literally decades if you do things right.
That leaf spot is very common, the plant will drop the bad leaves, the spots may be fungus I'm not sure, but they are environmental.
You'll see them spring and fall.
I'd not worry, it's more likely that you'll kill the plant with kindness than those black spots...
Atleast that's my experience...
