1) For dried up wax, I like to spray it with some spray wax and lightly brush it off with some soft brushes.
2) I think that will all depend on personal preference. I think a lot of people do the wash just to get rid of the dusting during compound/polishing phase.
For the old nasty stuff that's caked around moldings, I use a bamboo skewer. For about 2 bucks, you can buy a lifetime supply at your local grocery store.