3) What's more important to you, the performance of an eliquid or the flavor?
Flavor is what attracts you to the liquid, and performance is what keeps you wanting to vape it.
Vaping on a budget, I have to consider performance more than flavor ofttimes, just to make those tank coil heads last; if a liquid gunks the coils after a tank, I have to find something that will last longer and keep my gear performing. There are exceptions to that rule, but in the end, performance wins out in the long run.