So... got that new panel. There are improvements, but they are small ones.
Flashlighting/Clouding decreased. It's still there, but not as visible as before. Interestingly it's exactly where I expected it to be. I told both technicians to screw with less force. One did, the other apparently didn't care. On his side, there's a little clouding... but as I said, not very visible. I'm watching BSG right now, and I don't see it.
Banding decreased as well. There's still banding all over the panel, but at least it's not as pronounced as before.
And the small white spot is still exactly at the same place. But also smaller than before. I think this may be a manufactoring defect of all those panels (the technician told me both are Sharp panels).
So all in all an improvement, but not the improvement I hoped for. Will continue to monitor the situation (of course I will, that's what I bought the TV for, to monitor it...).