What is the difference between the (&F and Z) commands, Is it possible to send a reset command (&F or Z) with other commands in the same line, (i.e. AT&F0E0S0=2)? Is it necessary to wait some amount of time after sending a reset command?

The AT&F command loads factory default settings into active memory and can be used on the same line as other commands in most cases. It should be the first command on a line that contains multiple commands, as they are read and executed in order.

The ATZ command does a soft reset and restores the current user defined settings into active memory, when you use the ATZ command it should be on a line by itself. After sending an ATZ command you wait for the OK responce from the modem. If you have the modem configured with command response supressed, it is a good idea to wait for a couple of seconds before sending another command.