I see what you mean in the first photo, but it's just bug guts. :) I got back from a 2 week trip 3 days ago and have not yet cleaned it.
There are only two cracks in the whole RV. One on the rear wall and the one in the second picture. The rear wall crack I may fix with some eternabond and a sticker to mask it.
I will check the attachment to the cab to be sure. I may also partially disassemble the over-bed to see what's going on up there. While driving I notice flex, but only during period of high wind or big bumps.
I'm sure I can get the eternabond to look OK.
