Ortlieb Backpacker Plus Attachment
 

I am not sure if I am doing things right. I have the panniers pushed towards the back of the rack with the two top hooks in the rear section of the rack so the pannier doesn't slide too much front to back. Then I turned the bottom lever over the rear bottom triangle of the rack.

Here is where I am not so sure. At the bottom the pannier can move front to back since the "lever" doesn't fully tighten and the top "hooks" are a lot wider than then tubing on the rack so there is movement there. Now I don't think it is coming off without lifting the handle, but the panniers do move around some. Is this normal?

I would add some friction, electrical or duct tape to the bar where the top clips attach so it doesn't bounce around and you should be good.

Your Ortlieb panniers should have come with inserts to offset various tubesizes. I have 5 Ortlieb panniers and they all came with 2 sets for two different rack tubing sizes. It works for all racks that I have. (Performance, PlanetBike, Tubus)

The lever doesn't have to fully tighten the rack stay. A little play is OK left to right. What you want to make sure is that the lever does push the pannier backwards far enough that there is no play forward or aft
Duppie

What he said about the inserts, for the top. The lever thingy at the bottom is to stop the panniers from flapping out to your sides, like spreading wings. You can angle it against your rack to stop it moving either forward or back also but don't need to.