First, it's way too complicated. M20 is meant to strip back the more complicated aspects of 3.X, leaving the bare bones of each class. There's just a little bit too much going on there.
Second, my layout is pretty shitty.
Third, it's not generic enough - M20 is meant to be adaptable, and while you can add your own Vestiges or abilities, it's still kinda tied to those particular archetypes.
So, for the next iteration, I propose the following:
- Fix the damn layout!
- Maybe set the class so each DC gives a selection of abilities, instead of set archetypes, like so:
DC10 - gain one of the following abilities:
- a +3 bonus to a Skill
- a +1 bonus to a Stat
- a +1 bonus to your Melee, Ranged or Magic Attack Value
- the ability to wear Light Armour with no penalty
- A single 0-level Spell, cast as a Signature Spell
DC15 - gain two DC10 abilities, or:
- a +5 bonus to a Skill
- an ability from another Class (like the Fighter's bonus to-hit, the Thief's Backstab, or the Ranger's Dual-Wielding), aside from full Spellcasting. These are used as a first-level member of that class
- A single 1st-level Spell as a Signature Spell
- Two 0-level Spells as Signature Spells
...and so on. Then, I'd maybe make specific Vestiges using these rules (so an Ancient Lich, which grants a suite of abilities, at the appropriate DC), with drawbacks to scale more powerful ones out (like a vulnerability to Healing Energy, or a berserk rage, or something such). I'd keep those separate - as a Campaign Option (either use the "pick and play" or the set Vestiges, but it's one or the other).