I'm not sure if your home insurance would cover a technical malfunction, but it may cover other forms of accidental damage.

I'd like to repeat the test at f5.6 or f8 with the kit lens and a 50mm f1.7! Perhaps you lucked out with your sample, mine was fairly soft especially on one side. Vignetting was another issue.

Pentax need to get on the phone to GaGa's people. I can see her sporting some mad K-x colour combination. I expect she'd want more than just to keep the camera to be seen with it in public though. That girl's all 'ooh look at me i'm arty and subversive', but really she's all about the product placement.

John Hedgecoe used Pentax SLRs a lot! Expect we'll see more famous Pentax users with the 645d. I'm not particularly suprised there aren't that many famous Pentax apsc DSLR users to be truthful. Although i've seen a few who deserve to be well known, IMHO, even on this site.

I think the glass makes an important but subtle contribution, compared to switching between the on-camera colour modes or adjusting white balance. I doubt the glass accounts for:

That's absolutely correct... 90mm is too long for conventional portraits really, you are a long way from the subject, and a lot of the shots I have tried to do with this lens are bit tight, because I kept underestimating how far I needed to 'back off'!

However for taking candid portraits at a distance it's lovely, because the working distance becomes an advantage, and the DOF isolates your subject beautifully.

PM sent for AF280t flash....

I doubt the glass is having any real impact for the OP. My advice is to take a shot in RAW and then use the convert to jpeg function. You can then see the effect of each colour mode, and any custom made adjustments, on the image. Make a note of the best settings.

The AWB usually delivers more natural colours than the preset white balance settings. After all there are more than half a dozen or so types of light.

It's also worth seeing how the shots come out in a RAW converter like the one in photoshop. Usually more subtle and of course infinitely adjustable.

I don't think mine has the auto modes. However if you're bouncing the flash, its easy to get the exposure right manually and those settings will then work more or less wherever you are in the room, because the illumination is so even. A bit more trial and error is needed for direct flash.