WHeel not fitting into the dropouts? I would not worry about it but it surprises me. My Nomad, it does not fit that well but that is because I have a rack that is a bit too narrow and that presses the frame in. And does not fit that well on another bike that has 130mm dropouts when I run a 135mm wheel. Your Rohloff should drop right in. But, I would not worry about it.
I regularly ride a bike with bar end shifters, a bike with downtube friction shifter for front derailleur and brifter for rear derailleur, and my Rohloff bike with the twist grip shifter. I am ALWAYS eaching for the wrong shifter.
On the minimum ratio, I never tell anyone to do something that would violate a warranty.
Gears 1 to 7 are noisy, you are using a third set of planetary gears that is comparable to putting a Jeep or Land Rover into low range. Gears 8 to 14 do not engage those planetary gears. After the first oil change it is slightly quieter, but that is a permanent feature of the Rohloff. I did not get any vibration from it, but perhaps the extra noise is making you think that there is vibration?