What if I only charge it to 4500mah (It is a 5000mah lipo) Would that work?
Not really. Lipos charge with a constant current/constant voltage routine, they spend quite a bit of time/capacity at the constant voltage. So your example could easily cause an issue if the pack was significantly unbalanced. And you shouldn't make a habit of running lipos all the way down, it's recommended to not go past 80% discharge. Unlike a discharged nimh, you generally don't know where the pack is when you begin charging.
I don't have a balancer yet either, yes I know I should. I just check the cell voltages, so far I've not had a problem with the Orions and TrakPowers that I have. But I expect the day is coming, hopefully I'll have one before then.