I think that ultimately you'll have to do some trial and error to find out what works for you. Some poly relationships do have "out-of-balance" rules/expectations going from one partner to another, but still work because the one partner doesn't have the same interests as the other partner.
What tends to be universally helpful in the midst of uncertainty is to go slow (which you're already doing), communicate a lot (which I think you're doing), re-negotiate periodically as needed, and keep learning all you can about the ins and outs of polyamory. If you're already doing those things, then you'll probably be fine.
Love means never having to say, "Put down that meat cleaver!"