the corvette picture is not relivant. you can tell its the shoulder because of the rumble strips. either the vette ate the rear end and the truck pulled off, or vette driver somehow veered off the road and hit the parked truck. either case, that was not a 10 foot crash.
I have drafted in my full size blazer before, you can indeed feel when you enter the zone, and from my recolection it was not very close, certainly not close enough that i was worried that i would hit the truck in an emergency braking situation. of course i also dont talk on a cell phone, drink coffie, text friends, or try to turn my car into a mobile office full of distractions.
that being said, no, i would not follow a semi 10 feet off its bumper. and as to driving along side, thats just annoying to everyone who's trying to pass the semi truck. ive wanted to run people off the road for pacing the semi trucks before.