Ski jumps are not just a straight ramp that can fold down flat against the deck, they are a smooth curve from horizontal to the desired angle. If they weren't a curve, there would be a big impact and stress on the gear of the plane when it hit the start of the ramp, and it would probably bottom out or tip over or something else not very good. Due to the fact it is curved, there is no practical way of folding it.

The reason that the Wasp class can launch Harriers without a ski jump is the fact that they have a rectangular flight deck. If you tried to launch off of a Dokdo, one wheel would leave the deck before the other which is not a good idea (you could take off from the stern, but to do this you would use a lot more fuel as you would need a take off speed that was about 40 knots faster relative to the deck). Generally launching without a jump is a compromise, as more fuel is required along with a longer run up (meaning that you could park less aircraft and have fewer landing slots leading to slower flight ops). A ski jump would not take up that much space (probably only one parking space) as a large portion of it would be off of the current deck area on an enlarged superstructure. If they convert it, it will depend on whether they want it to remain primarily as an assault ship, or turn it into a carrier.

Back to the topic, I Have never used the gun/weapon platform category, can someone point me to a good example page where it has been used correctly?

Red Dawn? I don't know if it's completely correct, but I suspect someone would've said something already if it wasn't.