I don't think there is a one size fits all solution. I used to sit a bit low, but as I've aged, I've found it more comfortable to sit so my legs form a 90 degree angle at the knee. Snare is about 1/4" to 1/2" above my thigh, as is my floor tom.
I play heel down for the simple stuff and heel up for faster patterns. It's all about conserving energy for me. I don't do any more work than I have to :)
As for snare stands, I heard from another drummer that Pearl made a low profile snare stand at one point (maybe they still do).