hey Milk, congrats on the purchase again
it doesn't have to be run wet, but if you do so, you can go long periods without cleaning, which can be useful if you are shooting over 1000 rounds per day in a class and don't have time to clean. Obviously, if you have the opportunity to clean, there's nothing wrong with that, so long as you don't damage the rifle by over-zealous cleaning.
you can vary the buffer weight to delay the unlocking of the bolt slightly, so it trades lower chamber pressure (at the time of unlocking) for more reciprocating mass. Generally, you shouldn't go throwing different buffers in there unless you know what you're doing and need the extra weight, but at the same time, it probably won't break anything either. in fact, the change will be pretty subtle.
it doesn't have to be run wet, but if you do so, you can go long periods without cleaning, which can be useful if you are shooting over 1000 rounds per day in a class and don't have time to clean. Obviously, if you have the opportunity to clean, there's nothing wrong with that, so long as you don't damage the rifle by over-zealous cleaning.
you can vary the buffer weight to delay the unlocking of the bolt slightly, so it trades lower chamber pressure (at the time of unlocking) for more reciprocating mass. Generally, you shouldn't go throwing different buffers in there unless you know what you're doing and need the extra weight, but at the same time, it probably won't break anything either. in fact, the change will be pretty subtle.