I dunno, I enjoy most of the heart activities, and if I find something that doesn't interest me, I move on. You don't even really have to think about the daily achievements either, because they just sort of get done playing through the game. I don't find crafting terribly interesting, but it's still something easy to do if I don't have a lot of time to play. And events become more common as you level up. I've walked into areas to find five different things happening around me, and I've still got 15 levels before I reach maximum. Also you continue learning skills for your skill slots for a long time, and once you unlock traits you really start getting into some interesting customization (especially once you unlock the second tier, where the differences become much more noticeable). I think you're problem with the combat is that they keep it pretty simple at the lower levels to prevent people from becoming overwhelmed while they're still learning the basics of the system. It's becomes more complicated as you progress.
My favorite activities are the dungeons though. You haven't even gotten there to give that a shot.
Really though, if you're only interested in the personal story, then you're only interested in a very small fraction of the entire game. The reason the story line levels jump is that most people get enough experience doing other activities that it doesn't make a difference.