Though the peak 2 peak gondola is a tat bit expensive, it is worth going up the mountains to do it. There are 2 queues, one is a normal cabin, and the other is the 'crystal' cabin where you can actually see through the floor of the gondola. I would suggest that if there's a queue, skip the crystal and just do the normal cabin. It's good enough. More often than not, you will end up with the whole gondola(can seat about 20 or more ppl) to yourself. Why not eh?
Not much to do at blackcombs mountain but there's a gelato shop there and you can get really delicious whistler ice cream there.
If possible, please do the hike. Amazing and beautiful experience.
Feel free to visit my blog for more pictures and description of Whistler Mountain.