RE: prop balancing
Yes, you should balance props. Whether you should invest in a fancy balancer is a seperate issue. I have (and use) a simple finger-tip balancer. I balance all my props - and occasionally I find one that doesn't need balancing.
A simple "T"-pin held at an upward angle into the middle of the prop's shaft hole (so the tip is midway through the hole with the prop horizontal) will do for balancing. Scrape the front of the side that dips with a knife blade or sandpaper and repeat until it stays level.