1

Normally people take a 4 day jeep trip going one way from San Pedro to Uyuni, exploring the Bolivian altiplano, with the highlight being the Salar de Uyuni on the last day. This might possibly be shortened to 3 days, but that's 3 days one way. So, no the answer is if you only have one week, you don't have time for Bolivia, unless you rearrange your schedule, and fly back to wherever you need to go from an airport in Bolivia.

2

I saw the Bolivian South west a few years back and stayed in San Pedro just a couple of weeks back.

They are different. San Pedro is well set up for tourists with lots of accommodation at all price points and good restaurants. Travel to see the local goodies is by day trip mostly in small buses with a guide.

The Bolivian South west is a three/four day tour in 4WD with 4 or five others. Accommodation is mostly very simple.

For me the Bolivian three day tour remains one of the best things I have ever done.
San Pedro is Bolivia lite.

I would go straight through San Pedro or maybe direct from Calama to Uyuni do the Bolivia circuit then maybe use San Pedro for the R+R.

If you went direct from Calama to Uyuni it is possible to bail out of the 4WD on the third day at the Chilean border near San Pedro. When I did it there were buses waiting at the border. The tour agents in Uyuni organise the bus ticket.

While there is a lot of accommodation in San Pedro when I was there recently it was pretty much all full.

San Pedro is more expensive than Bolivia.