Chris D.
I'm no pro, but I did a very similar thing to you. When we upgraded from our first house, we kept it as a rental. And while I would do it again, it's not a move for everyone and there are some things to consider:
This is a risky move, and I would strongly recommend a cash reserve if you have a rental. My personal target is 10k cash. To me, the worst case scenario is that my investment somehow bankrupts me.
When we made the move, we lost around $250/month for several years. In fact now, 3 years later, we are still losing around $100/month. However, even ignoring appreciation, we were still increasing our net worth due to paying principle and tax benefits. Given our long-term time horizon, this is OK for us, but wouldn't be for a lot of people.
If selling would just break even, then there is literally no value in selling. This is not to say that renting is necessarily the right option.
I wouldn't get hung up on why you bought the house, or what your plans were. Plans are good, but base your decision the future, not the past!
Regarding the refi, going from 5+ to 3.25 sounds like an easy call. Even if you do not keep it as a rental, my hunch is that it would only take a year or so to break even - and it sounds like you will not sell in the next year.
IMO: Saving 10% is too low. If you have a decent job with no liquid assets in our late 20's, I would recommend saving north of 20%.
Sorry for the long winded response, but those are my novice thoughts.