As far as the rear wheel flange's cracking, if your purchasing from the original owner, they should have gotten a recall notice if their bike was an effected model. As for seals, they go bad from time to time.....period. When they go bad is anyone's guess, some go for 400k miles with no issue, some 30k. Final drive seal leaks are a 30 minute fix in your garage. The shaft seal repair that Olaf experienced is not common, but can happen, he had his done at the dealer, I did mine in my garage in 12 hours and for about $300 dollars. FYI, there are vast number of owners who have never had these seals leak. IF IT IS GOING TO BOTHER YOU DONT BUY IT. If on the other hand you understand that things happen go for it, the ergonomics, power, handling and overall feel of these bikes are not akin to anything else on the market IMOP and mine is the most perfect fitting motorcycle I've had in 40 years of riding. Good luck in your decision.
'11 - R1200R
'73 - XLCH