I wouldn't let the untrained monkeys at Kwik Fit adjust my seat.
Brake pads are easy enough, just look at how it is all together before you pull them out. When I have rebuilt engines I find taking digi pics as I go helps when putting them back together as you can easily forget where things clip together.
I agree, most novice DIYers could change front discs and pads without a problem, assuming they have the correct torx sockets to get the disc off the hub. Whilst Kwif fit may not employ the most competent fitters, even they, with the experience of repetition, would do a good job.
If Dirty Windows is going to keep his van for the next 5 years, then their offer maybe worth considering especially if its not wildly more expensive than his local garage.
We all know its a Kwik Fit marketing gimmick and most people who take them up on their offer will never come back for FOC replacements - sold car, accident writeoff, etc. so play them at their own game I say.