1. what are heel lifts for? how do they work?
2. are the shoes designated left or right foot?

L/R foot is designated by the straps going to the outside; you should be able to use them in reverse if you want, but it would be difficult to put them on and off. Also some newer shoes have the foot cup more specific so there is a specific L/R. The heal lift is for balance and foot position, critical for when carrying a pack and on steep climbs; on long days I have used the option on flats to just stretch my calves out. I wouldn't buy full size snow shoes without them, I have a pair of small rad feathers for running, but that's another ball game.

Actually they are left and right foot specific. In the past, the Lightning Ascents weren't specific on what foot you put the snowshoes on, rather it was left up to the user on where you wanted the straps to end up (inside vs. outside). However, the new 2010/2011 bindings do have a marking on the inside of the binding that shows which foot they are to go on. This allows the binding to fit better and hold the foot tighter with less discomfort, and take any guesswork out of which foot goes where.

1. The heel lifts are to improve performance while traveling uphill by raising your heel so that your foot is in a more natural position. This is accomplished by flipping up the heel lift wire with the powder basket of your trekking pole. 2. I do not believe that these are designated for right or left foot. Hope that this helps!