I am planning (my first) trip to China in March.

I'll be visiting Beijing and Shanghai in this trip. I have done some prelim reserach in this forum's past threads and looked at a guidebook. I still had some questions and would greatly appreciate some help.

I am planning to stay in Beijing for 4 nights.
1. Beijing Hotels. I have looked at a map and shortlisted some options after looking at the location and rates for my dates in March:
- St Regis (US$ 230 room only or 10k starpoints per night)
- Peninsula Palace (US$180 incl airport transfers & breakfast)
- Crowne Plaza
- Great Wall Sheraton (US 130 on exec level)
- Kempinski Hotel (US 180 incl breakfast, exec club & one-way airport transfer)
My main criterion for choosing was based on looking at a map and seeing which hotels were most centrally located and thus walkable to the main sightseeing/shopping attractions. (This would sort of eliminate the last two hotel options if I'm reading the map correctly.) Any other suggestions...
Also I'm an SPG Plat with enough starpoints to get the St Regis on points. (I have read all the great reviews on the St Regis, but looking at the rates, I think it is comparatively steep, given that there is no breakfast or transfers included.) The Peninsula Package seems really tempting and great value for money. So which would be better and what are the main differences between the 2 hotels. I could do split stays and do 2 nights each at two different hotels. Any input on an ideal combo...
2. Do any of the hotels (above or otherwise) offer an airport pickup service that includes meet at the aircraft gate and guide thru customs/immi etc (like some hotels in BKK do). Any ideas about the charge for this. Also what is the charge for a 'regular' hotel pick-up service?
3. How tough is immigration/customs at PEK. Time taken etc.
4. Is there any prepaid limo/cab service at PEK airport? And if so the charge?
5. In terms of walking, how suitable is Beijing. (Based on past threads, I would want to avoid the hassle of using cabs as much as possible).
6. Is it a safe city for a solo traveller who does not speak Mandarin/Cantonese. Both in terms of personal safety and money fleecing/overcharging.
7. In terms of exploring the Forbidden City, Tianenmen, Temple of Heaven etc would the hotel have a sort of day tour and what would the charges be like... Or is it just better to ignore this and do everything individually.
8. Great Wall: How expensive will it be to hire a guide and car thru the hotel for a day trip. Alternatively any group tour options for this...
9. Any shopping advice. Particular shops, goods, areas, malls etc.
10. What is a reasonable amount to allocate as a basic perdium in PEK for food, transport etc.
11. Should one purchase some Chinese currency before getting there, or leave till reaching PEK.
Okay. That's enough questions for now.

I'll leave the Shanghai questions for another thread!
Thanks a ton in advance.
cheers
AJ