Had two lights hooked up, pretty bright but wanted to add more. now have 7. not on relay just run to switch and switch has power from battery. the lights are really dim and wire gets HOT, i dont run them now, im planning on rewiring but not sure how. all lights are 55w each. i got a 40 amp relay, 40 amp fuse, fuse box and 10 guage wire to replace the 14. i was just going to rig up like diagram for relay and try it out, any different ways?

More switches and relays for better control.

I was thinking about running two lights per relay then one relay with three lights and run them to one switch. would it not work as well to run off one switch?

You could use one switch to control multiple relays, but all lights would be off/on at once.
I would want more selective control, by pairs for example. But that's just me.