I skimmed your post, but my Boxster is a daily driver. It was in the shop the first two weeks I had it, and it has been almost four months with no problems, but I am taking it in for a few common smaller problems this week. Overall, I am very pleased with the Boxster as a daily driver. It is fun and the repairs do cost a bit more than a sedan, but it is well worth it. Oil changes are needed only ever 15k miles so they aren't to expenive spread out over a longer period of time. My only complaint is the milage, I average about 280 miles a tank at 24 mpg, but that is 85% city and 15% highway. Once you get your Boxster in shape and maintain it it will last, my dad had his Porsche for 16 years.
Go for the Box and you won't be disappointed,
I would also check out:
http://www.iwantaporsche.net/BoxsterInfo.htm
http://mike.focke.googlepages.com/mikesporscheboxsterwebpages