[bme107]

The amount of painting a shop does depends on the size of repair work needed. They should blend the new area into the old. I've seen a few jobs where there are no visible signs of repaint, but you can feel the difference in the surface.

Can't answer the rest. Bad shop maybe?? Pics might help.

 

[bme107]

Clay should remove the overspray fallout from the entire car, even windows and trim.

 

[bme107]

For areas that were freshly painted you should wait about 1 month before claying, polishing or waxing. (areas that you wanted new paint or were blended to match)