Basic PCP air rifle questions

[jhinman]

I'm thinking of making the plunge to a PCP rifle, such as a 10M style, and am trying to get educated on the subject.

For a PCP rifle in the US, are the cylinders all rated for, and limited to, 200 bar? I see the advertisements that say 200 & 300 bar. I asked a vendor about the cylinder of the Hammerli AR20, and the response was "all air rifles in the USA are rated for 200 bar".

Does the cylinder pressure affect the shot, or simply the number of shots available from the cylinder?

The Hammerli spec lists a pellet velocity of approximately 560 fps. (I understand this will vary when different weights of pellets are used.) Is this a typical velocity for this style of air gun?

How significant is the pellet velocity? It seems that the faster the pellet gets out of the barrel the better, although my air pistol shoots substantially slower than 560 fps and has a reputation as being accurate.

Thanks for helping a "newby"!