Ok so playing the campaign showed me a lot of stuff I could be using, but with my feeble little mind, I cant find out how for the life of me where this stuff would be.

The headlight that most vehicles have when its dark would be an interesting floodlight for an infantry unit in my map. Where would I go to give this unit the ability to light things up infront of them?

you can open all campaign maps in the editor

What other units do this? I can't find the wraith in the default content, and I don't have the campaign opened up atm.

I have a feeling you'd just attach the light to a unit in the data editor. Or add an ability that turns it on (by adding it) or off (by removing it)?

If you play the secret mission 'Piercing the Shroud', Raynor has the flashlight in front of him as well. Perhaps you could look at that.

As far as I know, the units used in the campaign don't show up in the Data editor. You can place them, you just can't modify them unless you create them yourself.

Ill try looking into that. Ill let you guys know when my idea royally fucks up.

Just remember to supply your marines with duct tape so they can attach their lights to their guns and shoot while using the light o,O

You can add\edit stuff from the campaign, and raynor I do believe has 3 different variations of himself one is with a flashlight. To add stuff from the campaign go to File >> Dependencies >> Add Standard and check off the campaign one. After that move the campaign dependency to the top of the list, save the map, quit and re-open it and everything shud appear in the data editor you probably dont even need to quit just move it to the top.