Originally wanted to say "enchanted creature can't transform.," but I had worries that would make some rules issues. The solution seemed to be making the creature lose abilities. I also wanted the creature to not be able to attack or block, so I figured I could have the enchantment give that ability rather than put the ability on the creature? I don't know if that works

You over engineered this. "Enchanted creature loses all abilities and can't attack or block"

That said, this isn't 'strictly better' than Arrest, since there are corner cases when you want your opponent's creature to keep its abilities. But it's close to obsoleting a pre-existing strong piece of removal that was last seen at uncommon.

Maybe that's okay, or maybe is more appropriate. Or maybe . Cards like Turn to Frog tend to use ability wiping space in blue.