Well in my experience things are a little different (and I've been leaping out of planes since I was 18).
Static lines jumps (civilian) are carried out at 2000 feet. Static line (military) at 800 feet.
Freefalls start at 4000 feet and you pull at 1000 feet. Tandems start at 10000-14000 feet and pull at around 1500-2000 feet (military requirements are VERY different on this one).
Above 12500 feet you need to start thinking about oxygen although you can safely go up to about 15000 feet without. For high altitude jumps you need oxygen, strong pants and a good dentist (fillings tend to explode)

Oh and a lack of a sense of smell due to the uncontrollable flatulence
