Its fairly easy. You play the game fair by playing with the things you can do without programming little helpers and such stuff. If you need a faster refire rate get 8.33 guns, they are good as well.
To the lag, it does not only bother you but also makes you jump in your opponents view, so you got an advantage there as well.
If you dont want to die pick your fights more careful or train to get better. Its not that easy to get into PvP here but it is very possible.
Also dont mind dieing, its a game and you dont loose anything if you do. I guess most players tend to die often in bigger fights, I see no problem there.
But getting an advantage by means not given by the game is outright cheating, its right everyone can do that but just as well everyone is able to use other cheats.