God bless her and all who sail in her.

25 KTS top end seems a bit slow for a strike carrier. Then again, they don't have to re-position or achieve certain wind over the deck for fixed wing operations... I guess she's more akin to USN's LHA / LHD amphib fleet than it's CVNs.

Fair winds and following seas.

Why do some carriers have ski jumps and US carries do not?

Will she still be able to get into port for maintenance and under bridges once the seas rise, or will they have to overload her to run lower in the water?

Interesting that she doesn't have the angled flight flight deck design like the American CVA's have. It's my impression that the angled deck design permits simultaneous aircraft launch and recovery; in addition, I see no mention of propulsion power... is this carrier nuclear or conventionally powered? The twin island arrangement is certainly a novel idea, and makes a lot of sense: the forward tower to focus on the vessel's operations, and the aft tower handling aircraft management. Fair winds and following seas to the crew!

Diesel and gas. Probably electric propulsion. Why? Cheaper. Britain has it's own oil so has a secure supply. Can come and visit us in NZ as well without nukes.

It has the ski jump because its air wing will consist mainly of the F-35 STOVL version. Short Take-Off Vertical landing. Planes loaded with fuel and weapons will use the ramp as a booster to get airborne. They'll be lighter upon return due to burning fuel and less bombs and missiles expended in training or battle. So they'll land vertically.
That's why carriers for STOVL aircraft and helicopters don't need the angled deck to handle simultaneous launch and landing. The UK has much experience with this with the Harrier jets.
25 knots is very likely understating the carrier's top speed, just like the USA doesn't publicly tell the maximum speed of their warships, especially the nuclear powered ones.

Its already obsolete and its a floating coffin! The Chinese have developed an unstoppable missile capable of destroying a whole aircraft carrier, in one hit, at a fraction of the cost of this monstrosity. The Navy has a history of building white elephants, and this one has to be the biggest! I feel for the poor sailors who have to man it, living under the threat of instant annihilation, is not nice. I lived on a 'V' bomber station, during the cold war, under the same threat.

Reason for ski-ramp is COST. No angled deck possible, either.
https://www.theregister.co.uk/2017/01/11/us_navy_emals_woes_uss_gerald_r_ford/ Now these ships are limited, even if/when the F35B is taken aboard; that is the VSTOL version which carries a much reduced payload & has shorter range than the F35 which must be catapult launched.
Altogether QE2 & POW are compromised despite their high costs, the third vessel having been cancelled meaning at times there will be only ONE operational & even neither of them, in case of breakdown.
As noted elsewhere these are extremely vulnerable, valuable & difficult to protect, much like the battleships of WW2. I don't think they are anything to crow about. Big mistake; the French had the sense to pull out of building one as a 'Concorde'- type collaboration.