I think there is an error in Hit Point Regression. What you mean to say, I think, is
Hit Point Regression: When the paragon creature reaches 15th level, each of its rolled hit dice changes to the maximum die roll and it gains the remaining +12 per hit die (If it had 20 fighter levels before the paragon progression with a constitution modifier of +0, its hit points would become 20*10+20*12 = 440 HP
Or have I misunderstood something?
From your example I take it that this class might be taken by epic characters?
If so, I think it gets bonuses to attack way faster than an epic fighter would (+1 or even +2 per level, instead of +1/2 levels); saves go up faster (+1/level instead of +1/2 levels)- faster, even, since I am not counting the ability increases; there is a synergy between the rising ability scores and the comp bonuses to skills that makes the lack of skill points almost irrelevant; ability score increases would normally cost 6 feats per level.
If you spread out these benefits over 30 levels, then it would be halfway reasonable. As it is, - no way.