Harrier ramps are inclined at a ten degree angle, I think
HMS Invincible had a 7° ramp to begin with but this was later increased to 12°, which is the same for Hermes, Illustrious and Ark Royal.
Whether you like it or not, the ski-jump principle is basically about partially-ballistic trajectories giving "runway in the sky" to use to accelerate to a speeds where >+1g Nz is available. Your basic sums are wrong, as the ramps are curved in profile rather than straight as suggested by your simple trigonometry. I've walked up more than one, but find some pictures on the internet if you want evidence. Some KE is traded off on the way up the ramp, but nowhere near as much as you think bearing in mind the ramp length and *exit* angle (entry angle is zero). You are correct that rolling resistance increases on the ramp, but that is trivial and I can't remember it ever being accounted for in any performance calculations I've seen. What matters far more is the upward component of velocity at ramp exit. As an additional benefit, this also means that even if the engine misbehaved when leaving the ramp, the aircraft would have signficantly more time in the air than the equivalent situation with a flat-deck launch. Significant in terms of time for stores-jettison, engine limiter-tripping and/or ejection anyway)
You should probably have a look at how flightpath angle, pitch angle and angle of attack are related, as you seem to be confused about that too. Ever wondered why Harriers on the ground have a marked nose-up attitude (assuming the nose-gear oleo is correctly pressurised, which in many static museum examples is not the case)?
What types are those?
1st generation Harrier (i.e. not Harrier II) variants are not as generously endowed in the wing department as the Harrier II family. I have only ever seen a handful of Harrier flat-deck STOs and they were at lightish weight, so the angled deck of PA Charles de Gaulle sufficed for length. Loaded up with external stores, I can easily envisage 130kts being required and in that case CdG's angled deck wouldn't have been long enough, even with its 4m extension (sorry mes amis, couldn't resist!).