Welcome!
Concerning the Liberon products you mentioned - while general high quality furniture finishes work well on flat work, pen turning requires a different approach, even if you do decide to use them on pens. The finish of varnish, shellac, urethanes and even lacquer require more time than most people want to put in on a pen. A few people do, but look at it like this - If you take your time to drill out a blank, glue the tube in with CA or 5 min epoxy, turn the blank and sand it - less than one hour, and then you wait a couple of days on the finish to cure.
Another thing you have to watch for is the way that pens are used as opposed to furniture. A pen is handled by oily sweaty hands, in pockets of perspiring people, in contact with moisture and heat as well as cold. Can the finish handle this. Most fine finishes can, but it requires a master finisher to know how to "cure" the different finishes so that they can stand up to the constant abuse. CA, Lacquer and oils do the best in reasonably quick times, but the lacquer does require a cure-in time.