License Transfer to my new email?

You can just use your new email when you license, assuming you have activations available. Running out of activations would be the only reason to purchase again (I'd encourage you to just support development, but I'd rather you not pay again right before marked 3 comes out as i won't be able to offer upgrade pricing.)

Paddle makes it really hard to change the user e-mail on my end. You can actually use any email when entering a valid license, so I don't usually bother.