"1) Will DVDs made from footage shot in DV-30p (non-HD) play on a blu-ray player? "
I don't know if you've actually recorded 30p if you recorded on DV. I certainly could be wrong, I've just never seen a camera that records that. Either way, Blu-ray players should be backwards compatible and be able to play SD DVDs.
"2) If I buy a new HD camcorder (about to do) and shoot in 1080p30, can I make BLU-RAY DISCS? (as opposed to shooting in 60i)"
Only really high end cameras truly shoot 1080p30. If you actually got your hands on one, sure you could burn your project to Blu-ray.
I am under the impression that you think it has to be progressive scanning though. It doesn't. Blu-ray can be interlaced video too.