[Less Rant, more actionable ideas]
Hi gyt! I'm thinking about the 2 points you made, on PROGRESSION and NARROWER CLASS SKILL TREES.
How about the passives then? Because I presume what you intended to narrow-down was the set of active skills of each class. So would it be the passives which actually "make you get better", giving you better abilities and adding more power to your active skills? That kinda makes sense to me, but let me know if that's not where you were heading with this 
That is largely where I was heading with it. But... what I would ideally like to do is create an entire overhaul mod that discards the current class and 100 level system for something different. These are the two ideas I have kicking around in my head:
1) A classless system wherein you can invest in ANY of a number of talent trees that are composed of passive and active skills (much like Dragon Age: Origins). Investing a skill point into the first tier of a skill tree would unlock the second skill and so forth. Each skill would have only 1 rank. So a talent tree might look like this:
Way of the SwordTalent 1, 'Swordsmanship': Reduces stat requirements when equipping one-handed swords.
Talent 2, 'Blade Expertise': Activate this ability to greatly reduce fumble chance and increase dodge and critical chance, but attack speed is reduced (active).
Talent 3, 'Sword Soul': Increases damage done while wielding a one-handed sword (passive).
Talent 4, 'Lunge': Quickly close the distance to your enemy with a powerful strike that deals extra damage (active).
This system would be excellent for supporting single-player play because of the free-form progression that is allowed by a classless system like this.
2)The other idea is a class system with more narrowly defined roles, which would be ideal for a cooperative multiplayer mod where each player has a unique role to fill. This could be an adventure-style hack n' slash or a competitive MOBA-like (though, I'm not really interested in making a MOBA, something more akin to a fantasy-themed, 3rd person Halo or Tribes).
In this setup classes would have 3-4 active abilities and a few passives. Progression would be much more limited than in the classless model but would provide a few choices where skill points could be invested. Again, each passive and active would have only 1 level. So an example of a passive and active might be something like this:
Class: Swordsman (role: balanced, mobile melee fighter)
Active Ability: 'Lunge' (as above)
Passive Ability1, 'Power Lunge': Your lunges deal more damage.
Passive Ability 2, 'Surprise Lunge': Your lunges gain a chance to stun your targets.
So, the passives would augment the active of your choice and would slightly modify the way you play, but your role would remain relatively static. Choice might be introduced where one passive must be chosen between two options, the passives being mutually exclusive. The real focus of this system, again, is to encourage teamwork. So there might be, aside from the melee fighter, a scout, a tank, a ranged attacker, a support character and a debuffer/debilitator. No healers, though. They water down strategy.