Lee production bottom pour 20lb pots are a great deal! It works well even though it's cheap don't be thrown off. I have one and it's great!
Yes if the drive bands are not filled out, use more heat on the mould.
if you head over to castboolits you'll be able to find the answers to all of your questions and more. Newbies are welcome over there.
http://castboolits.gunloads.com/