Welcome to the forums. To answer your questions:
No, unless you decide sell the master rights (ie all the rights to your track) outside AJ, in which case you’d have to remove it from the site because you don’t own it anymore. This is a very rare scenario, and most people would never want to sell the rights to a track away anyway.
All licenses sold on AJ are just that - licenses. They grant a buyer a single-use of your music. You still own all the rights and can continue to have it up for sale for as long as you want.
Nope. That’s the beauty of stock music
Hope that helps! Good luck on your journey through the Jungle.