Hi,
Yes, I would think the levelers would have included the tool to use them. My trailer did not come with a jack to change the tire, I think that is common. Bought a scissor jack at Walmart.
If your truck's light come in contact with the trailer, there is something wrong. You're probably at way too much of an angle.
Not sure about the coupler releasing. I never really had a problem. Was the trailer on a hill and putting pressure on the ball?
Lastly, you can get a cheap level at the dollar store that's about 10" long. Or, you can download a level app for your phone. I-phone has one built in. I also use the counter top.
