I don't understand your first suggestion, aside from that it would be far more complicated and ackward that what I am currently doing. Skill ranks are already taken into account in the modifier on the roll, having them also apply to how the roll is made is convoluted and a major balance issue.
Your complaint was that personal skill is insignificant next to the roll itself until mid levels, which is entirely true, but stems from the average roll made on the dice (11 or 10.5,) being much larger than your skill modifier, and has nothing to do with the probability distribution. If you want to fix that, you need to scale the average roll made, not how frequently that particular number comes up.
For the second, that seems a very overpowered way of doing things that also completely ignores the differences in crit range and modifier in different weapons.
I always considered this to be an overcomplication of the system, but as for being overpowered? Look, realistically speaking, if someone stabs you in the heart, you are dead, regardless of these so-called 'hit points' that high-level characters lug around. Think of it as a built in Massive Damage system.

If you want to incorporate different crit multipliers, simply apply it to the first crit confirmation. (Of course, a system of Dodge/Parry skills would probably be needed to balance things out properly.)
Think about all the 1d8 and 1d10 weapons that would be made much more mechanically similar under this system.
Good.
Oh- another suggestion- apply strength bonus to damage rolls only, but allow margin of success on your attack roll to boost damage instead. Apply dex bonus to all attack rolls, but cap maximum dexterity by damage die in a fashion similar to armour caps. This forces players to trade off between high-damage, low-to-hit weapons (like greatswords,) or low-damage, high-to-hit weapons (like rapiers.)