Hi
not really a iceberg, more like a slushie

..... the splashback is glued onto your wall and when they cut the vent out it left sharp corners, a little bit of flex and it cracks at these sharp corners. being a laminate material it don't flex like the rest of the wall
depending on the repairer and the panel they will either overlay a new piece of laminate or trim around the cupboards/benches and pull it out and replace. either way has it's good and bad points. usually we try to remove any overhead cupboards and then cut a panel to fit, it's very hard to get a good fit as 99% of the time nothing is square, even a 2mm taper is very visible so it's pretty fiddly repair, so we try to hide the worst edge behind a cupboard where it's not seen
Most of your cupboards have a rubber lip stapled to the back edge to cover any joins, this needs to be cut off and we just put a nice bead of coloured silastic down in it's place. i reckon it looks better than the rubber exspecially in a food preperation area, much easier to keep clean.
one of these i did i had about 6 goes till i got it right

panel would snap just from handling it wrong and i was trying to tuck it behind 3 cupboards at once PITA
I would honestly say that the Jayco is one of the better built vans, they have put a lot of time and effort into building them quicker, but the quality is still on par with other vans costing a lot more.
I remember a 2 year old van of another make that i was recladding after a swipe with a pole, took the cladding off and the wooden frame was rotted out from water ingress 1 metre up the side ...... ended up writeing it off as too costly to repair and that was a $50k van .. not saying the jayco are waterproof, but any water damage is usually only cosmetic, not structural