Hi Paull, can't comment on most of your questions (yet) but the wheels I suspect are to do with the polished finish - just like Themas, Dedras, Subarus and every other polished finish wheel, they look fabulous when new but unless you are anal about cleaning them, they will corrode quicker than a normal powder coat type finish. In saying that, all they need is a stone chip to break the lacquer or top finish and that is the start of it. Look great when new, rubbish for longevity. The wheels on the 2004 one I have just bought are 2 perfect, 2 starting to bubble - but they are a normal powder finish and the 2 can be refurbished at reasonable cost. Refurbishing diamond finish is trickier and will need a specialist.
Lindsay
Just a little bit of help here if it is any good (I meant to tell you about this by email, Lindsay, so remind me and I will give you more detail). My (ex-Lindsay!) Kappa has lovely lacquered wheels, and they aren't that old, having been replaced by the owner before Lindsay. However, I obviously have the same problems of poor longevity as everyone else, but I have managed to slow down the decline considerably. In winter I spray the lacquered finish with WD-40 every time I wash the car (that's usually 2-3 times a week in winter because I am pathological about salt). It is extremely effective at keeping the wheels going longer, because any little chips or cracks that the lacquer gets are protected by the WD-40. Just be careful to cover the brakes (it is best to take the wheels off the car to do it, although that's a bit of a burden on a daily driver!). The only downside of course is that the WD-40 attracts dirt, so although the wheels are protected by a thin layer of oil they tend to look really grubby. But they do in winter anyway, and I reckon having grubby wheels for 3-4 months a year is better than having corroded ones.
Finally, we just did some work on an absolutely fantastic 8V Integrale that had been imported from Japan, and although the wheels (the original pepperpot ones with the gunmetal centre but unpainted lacquered edges) were 90% perfect, the owner wanted them to be 100%. So we searched around, and to my considerable surprise we managed to find a refurb specialist in Cornwall who did them for about £75 per wheel (I am not 100% certain on the price because it was a few months back, but that's within £20, and it was certainly less than £100). Although that is a bit more expensive than our usual wheel refurb man (things are cheap down 'ere in darkest Devon!), it is only about the same price that I usually hear quoted from refurb people 'up country'. And it is considerably cheaper than it would cost to strip them and paint them - I once stripped the lacquer off a set of Thema wheels, and just doing that bit of the job alone took me 3 days!
I hope that helps a bit - if you have a set of lacquered wheels that you want to get done let me know and I will try to help.
Cheers
Alan