I have some trouble understanding the issue with someone driving 50 on a 65 MPH road. Perhaps it's a cultural thing.
I have in several occasions driven 50 on a 75 MPH road (with maybe 15% of the cars doing over 90) without incident and it felt pretty safe to me. Large speed differentials between lanes are a common thing here. You can stay on the right lane and do your thing, as long as you accelerate adequately if the need to overtake arises.
__________________
|