Is it possible to blow a switch? everything is hooked up right, but the switch won't turn on the lights. The switch glows green when you turn it on, but now it doesn't glow at all.

 

That is true. But as long as the circuit will carry the full load, then you can connect as many as you like.

Yes. Possible. Make sure all you devices ( switches, relay, fuse holders and fuse ) and the conductors are compatable with the load connected.