I've got an '02 R1150R, took delivery of it in August '02, I've done most of the work on the bike .
When it comes to the engine management system and ABS, if the bike has it, without a code reader, you pretty much can't do anything if you have a problem .
There are readers that plug into the diagnostic plug on the bike, they are around the $300-500 range, depending on what you get, I think there is an option, to where you can get a laptop computer plugged into the reader and get 'real time' information .
As far as setting the valves, I have performed the job twice in 37,000 miles, barely needed adjustment when I did check them .
The bike isn't difficult to work on for the most part, but with RS or RT fairings I'm sure that would complicate things a bit .
The bikes for the most part don't need much attention, kinda like 4 wheel vehicles these days .