I know exactly what you mean. I usually converse with the person first. I'm not looking for crazy speed, I don't take boasters, I let them know what I'm looking for. So far the people I've met have been very respectful of my limits and I have been good in listening to what they need from me as a passenger (i.e. when they stop, turn and speed up).
We go for slow practice rounds to see whether I am picking up on the techniques before we go on the highway. I don't think anyone is truly out there hoping to test fate.
I appreciate the concern. Wish me luck