What an odd thread.
First of all, I always have my own pen because I prefer to write with a good pen when filling out a document. My husband has his favorite pen clipped to his checkbook.
As far as not touching things, when one eats out they touch the outer/inner door to the restaurant, shake hands with the owner or greeter if they know them well (in our case often hug them) then the seat/booth they are sitting in, probably the table, the menu, the salt and pepper grinders, oil/vinegar cruets or other condiment containers, etc. - not to mention the probably germ laden food from the servers. Heaven forbid they should need to use the restroom 
Worry about all of this is so silly unless one is so immune compromised that they should avoid the public as much as possible.
Would I go out of the way to handle fecal material from a stranger signing up for Ocare insurance? Uh, no. Would I worry about it incessantly? Uh, probably not. And, at least he warned you, OP, so you knew not to shake hands 
As far as the mechanic not using the seat belt in the vehicle, one would assume he used the door handle and the steering wheel.
I just live my life and realized that we are surrounded - just do our best and carry on!
I remember the expose where it said almost every single theatre arm/seat was contaminated with fecal matter.
So, pass the popcorn please
and enjoy the show !
ETA. My grandparents had an outhouse and both lived well into their 90s....