Interesting post,this seems to back up what over 95 members of the
Buying A Former Rental thread have encountered as to the Life expectancy in miles, they all seem to have no problem with theirs, it seems that proper maintenance is the key, Also I agree on the following the transmission maintenance schedule,I have all the records for mine and it has been done and I have continued with it.
The Generators, there doesn't seem to be any that have problems so far and most have over 800 hours,mine has over 900 and I have had no problems.
As far as the Chassis I agree that I would stick with Ford Or
Chevy I have had no major problems just
Proper maintenance with my Chevy based Class C with over 100000 miles on it
Then there is the tires I agree with your assessment on that, I changed mine out at the 5 year mark to some Very Good Michelins
This post may be a good reference point for the Rental Thread.