The white fluffy stuff are cottony maple scale, a sucking insect that can create plenty of drippy honey dew (like aphids). The other insects are some kind of beetle pupae, don't know what kind. They look quite a bit like ladybug pupae, but I don't know for sure what size your insects are. Mind you, your tree could have aphids, as well! Very common with maples.

It's hard for me to tell from that distance. Can you take a closer photo of the leaf shape? You may be able to ID it yourself by googling images of "Norway maple vs. Sugar maple" or similar. http://oregonstate.edu/dept/ldplants/images/acpl-sa2.jpg http://homepage2.nifty.com/chigyoraku/worldleaf1.jpeg

We have sugar, red, and amur maples all over the place here, and I'm pretty sure it's not one of those. If any, *maybe* Amur. Try the UBC maples forum. There are some folks there who seem to know every species out there-- This is what I'm used to seeing for Amur maples (more sharply toothed, more jagged): http://oregonstate.edu/dept/ldplants/acgi3.htm Acer rubrum tends to have three lobes that are of a similar size: http://oregonstate.edu/dept/ldplants/acru5.htm And sugar maples are the obvious flag shape: http://oregonstate.edu/dept/ldplants/acsa4.htm This page might help you find a photo that looks like your tree: http://oregonstate.edu/dept/ldplants/1plants.htm#acer

Looks like the juvenile (young ) foliage of a Norway maple, Acer platanoides.