It is there is already. You can see forging status in uppper menu:
http://prntscr.com/kq0ys4
You can on and off it by pressing on forging label.
But forging is still to support the network and testing purposes right know isn't it ? or does it actually lead to some kind of rewards ? Anyway if it supports the network i will try to set one up.
Forging makes new blocks, so yes it is necessary for the network to function and exist. In reward the forging account gets transaction fees.
The more nodes in the network the better. If you want to support XEL you should definitely set up and run one.