Got it, so you pay to volunteer, my friend is looking to make a bit of money. Thanks.

Yup, you pay. Most of it is tax deductible, so it is a pretty good deal. We were besieged by school personnel looking for English teachers for pay. I am sure there are many opportunties on the web if your friend were to do a search.

We found Beijing very walkable, as long as you don't try to do too much at a time. The Back Lakes area between the Forbidden City and the Drum Tower is particularly suitable for walking, in fact I don't see how you could do it by taxi. When you get sick of it you can always head for the nearest sizeable road and flag a cab back to your hotel.