Did it feel like the vibration was centered on the pedals? The only true mechanical connection any of the pedals have is their pivot/mounting point in the footwell so it could be vibration transmitted through the body. The higher RPMs, I would be willing to bet is a matter of your perception. Assuming the Jeeps you have driven in the past were geared with 3.73 or possibly 3.21, any given speed when running 4.10 will show a higher RPM. Tire size will also affect the RPMs.
Diagnosing the vibration, on here anyway, will be difficult at best and impossible at worst simply because there are so many variables.