Nice plugin, looked though your code and here's a few suggestions:
When creating GangMainMenu you don't need to put the whole menu in an if statement, only the parts that are different for every rank.
Most of the huge if-else statements in onPlayerSpawn can be changed to switches.
Try not to create huge functions, divide them into smaller ones, so that you can reuse some of the smaller ones and the code should become shorter (and easier for others to read
)
All in all, after TQueries, I will put this one to field testing
Private Plugins: Jail Rank | Rebel Zones | Round end Rebels | Freekill Guard