Haha, all battles are optional, look at Greiger who skipped the gym even. But levels come from battling. It's okay to, like, describe the battle without typing out every single order a character gives though. Like I did in my Academy battles I believe. So I don't really know why I'm making an effort to describe so much in my battle right now as it's only myself I really have to convince in order to get levels O.o.........