Can I use one license for paperback and hardcover editions?

Yes. Unlocking a book covers all of its wrap variants: Amazon KDP, IngramSpark, Lulu and B&N Press, in paperback (perfect bound), hardcover case laminate and dust jacket. That is up to 11 wraps for one book — four printers times three bindings, less the combinations a printer doesn't sell at your trim, which the menus hide rather than let you export. You can build one of them or all of them on the single license, and you don't pay again per binding.

The same idea applies to the interior: one interior unlock gives you both the print PDF and the EPUB for that book. As long as it's the same book (project) in your library, you're covered. (A genuinely separate title is its own purchase — see What does "per book" mean?)