With a routing like that I'm assuming this is a reward ticket and not revenue. (I could be wrong of course!)
1) The safest thing to do when you check in is simply ask. "Where's the lounge?" will get you everything you need to know.
2) Typically the answer here is no, but #1 will get you the definitive answer.
3) See #1.
4) Direct-boarding gates are nice but I've only experienced that once in FRA. To the best of my knowledge, they don't exist for *A at the places you're going to. But times change so you never know ...
Another note - last time I was in PEK we used the Air China lounge. It was upstairs to the left as we cleared security. The lounge had seemingly slim pickings for food but I discovered that if you just keep walking to the end of the lounge you'll find the restaurant / bar area where all the good stuff is.
Enjoy your flights!