Can spell speed, and skill speed be combined into singular haste stat?

[Absurdity]

While I agree with your overall premise on your last point it’s not really that haste needs a buff it’s that crit needs to be nerfed

Even if they nerfed crit it wouldn't suddenly make haste viable.
You will only take as much of the stat as necessary to make your rotation work within the 2-minute buff window restriction.