Well I'm jumping in late here and will only try to add new comments.
I've had my MINI 7+ years and 100,600+ miles now.
The only real problem I've had (that I didn't induce myself) was a power steering pump went out around 50K miles (during NCAC

of all places)
The right rear suspension link broke in Laurinburg on a hard left turn. After some research it was likely due to me putting stress fractures in the link after using that as a tie down during a transport. Live and learn. The adjustable after-market links are great.
As for mileage. On average I get high 20's during spirited daily driving and 35+ when gas is $4.00/gal and I am in conservative mode.
There aren't too many cars that make a great economical daily driver and a fun car to play with on the weekend and the MINI is surely one.
My only issue is the reduction pulley I added early in the car's life on the supercharger which puts me in SM class. I know that is the rules, but I would not have the car any other way. It adds 15-20hp at the peak.
I can't imagine people not loving that supercharger whine.
Maria can't have that supercharger whine with a turbo so she makes some off comment about it. I think she is jealous.
Do not get a sunroof if you plan to AutoX. You are as tall as I and I can not sit as upright I would like with a helmet on. The sunroof take 1 or 2" of clearance.