A few "answers"
1: The photo is a bit of a cheat the lens makes the QE look nearly as big as the GW, it isn't.
2: The two islands are a solution to a lot of problems. First, they are tied to the main engines - these are positioned in the sponsons, this eliminates large uptakes in the hull and the position minimises signatures and makes replacement easier. Second, they are separated to allow more deck space and, as mentioned, to split the bridge and air ops, but more importantly the electronics
3: The ski-jump is there for the same reason it was on the Invincibles, to improve the performance of the embarked STOVL jets. The fact why the RN has STOVL jets instead of cat-and-trap comes down to government parsimony and idiocy. Originally the STOVL jets were chosen when Government policy was tied into amphibious assault. A 40-odd STOVL carrier could (theoretically) generate more sorties in a day than the USN super carriers (120-plus). This was true-and-false. True, in as much as the STOVL jets could take off and land much more quickly and the ship didn't need to sail that long into wind. False, because the USN flew longer missions and were larger groups/strikes. (This claim irritated the USN that they actually did a special demonstration whereby a carrier performed a special single day surge and got something like 135 sorties a day). ANYWAY, the ship was ordered with the intention of employing STOVL aircraft BUT with the option of EAST conversion to cat-and-trap. THEN the stupidities happened. The spec of the ships were changed, the timescale slipped and what were meant to be relatively cheap ships increased in budgets (!) After a while, when the F-35 STOVL version price went up and performance down, Cameron wanted to re-order the ships as cat-and-trap carriers (to save money and have better performance aircraft). NOT IMMEDIATELY, it was revealed that one of the cost-cutting decisions made before meant that the "easily converted" configuration had been dropped and so Cameron had to publically back-track and go for the STOVL F-35 - just another of the fiascos that was/is this project.
As mentioned elsewhere, the RAF are meant to operate off the ship as part of a "purple" operation. HOWEVER (the farce continues) the RAF doesn't like having its weekends ruined by being at sea and has used its role as lead service on the F-35 to try to get out of going on board and recently even tried to change some of the UK's F-35 buy changed to the air force only version.
The chances of the RN getting enough STOVL F-35s to fill both ships is marginal and the problem is incompetent defence procurement, incompetent government and an RAF who doesn't like to operate at sea.
Me bitter ? Just a bit.