1:
http://395travel.com/2: Take a walkabout around the Portal Area to familirize yourself. This also helps with acclimatizing. Also, check out Orientation notes for Whitney first timers to the left.
3: Try Elevations in Lone Pine. Again, see orientation notes. According to their website, they do not have ice axes but call to find out.
http://www.sierraelevation.com/4: Yes, they sell ice.
Pond is stocked every Tuesday.
