will i be able to put a skinned gun on the workshop for others to use? or will it not show up for them?

Anything requiring a dlc3 vpk won't work with the workshop.

It works and now I have the ugliest red rainbowgun in the world. Thanks so much

Yeah, it did take forever and ever to launch the first time I opened it after I added the dlc3 folder. After the dots went orange (took like 15min), I opened the console and changed the map from it. No need to relaunch.