HI, and welcome to the forum!! You will love having a pool!

I can't answer your pump/filter questions as well as some of the other folks can, but the good news is they should be by soon with some info for you. I do want to comment, though, that if you drain the pool the liner will shrink and you'll have a very difficult if not impossible time trying to stretch it back out again. Pooldoc or Waste can perhaps shed some light on whether you can re-use the liner, but I wouldn't drain the pool until they say so. Although the water may look bad, I'm willing to bet we can help you get it cleared up without having to drain.