Weapons: I like Baron Opal's approach to weapons. However, I think I would prefer if it was more 'generic' and the effects thus could apply to the weapon at hand. That is, let there be a weapon mastery feat chain. 5 lvl tier, as suggested by Baron O. But the benefits gained depend on the weapon being used at the moment. (Or it could be the wielder's choice which bonus to apply). Let the chain be bonus feats only to warriors.
This will avoid the 'married to a weapon' trope of D&D that I really dislike. Once you have spent one feat on a given weapon, you use that type exclusively for the rest of the campaign. In my campaigns, weapon focus applies to 'melee weapons' or 'missile weapons'. Same with weapon spec.
By making the feat chain generic, warriors are badass with all weapons, in different ways. Might keep them up to par with spellcasters.
Another very simple solution could just be to increase the damage multiplier of rapiers etc. by one. So longsword 1d8/x2, rapier 1d6/x3.
Armor: Think this is very difficult. On one side, spending three talents should be awarded, on the other side, this will make heavy armored warriors impossible to hit. The problem is mainly due to magic armors, shields, amulets and rings. Without these, a fighter could end up around Reflex 43 which is still crazy, but with them madness ensues.
Core: Acore ability for each class could be to be able to use AP's for things normally not allowed (increase fort defense for fighters after knowing the result of the dice) plus when using APs for this and core activities (attack, skill use, spellcasting, domain power, etc.) increase the die to d8's (stackable with that feat, so you can end up with d10's).
Other core uses could be access to any feat on the class' bonus feat list, access to a talent, spell, and such.
You only get the core ability of the class you start in at 1st lvl.
Magic: My non patented shot at a magic system.
In very short, pick a feat named Gifted or such. This allows you to make Use Magic skill checks and so on a la Force Sensitive.
Now, you can learn spells. You can learn spells of a level equal to half your Mage level (round up).
Take the feat Magic Training. This feat is on the Mage class' bonus feat list! Each time you pick it, you gain spell picks equal to Spellcasting Stat +1. Use these picks to learn a new spell or another use of a known spell. Spells cost half their level in picks to learn or use more than once. 0-level spells costs ½ pick.
Spells recharge as per Saga. However, any and all 'out of combat spells' (buff, healing, fly, invisibility and so on) cast out of an encounter is considered spent when the next encounter begins! This is a bit of metagaming to control unlimited healing, buffs, etc. If you have two slots of healing, you can use two heals between encounters, but not more, and when the next encounter begins, the slots are not available.
Feats can help out here, as well as APs. Maybe feats can allow swapping between spells?
Meta Magic is done via talents. Each metamagic talent chosen allows the use of one use of metamagic per minute. Each talent can be taken multiple times, to be usable more than once per minute (or stacking). Half level limit for learning spells apply. I was thinking that using meta magic would be a full round action.
I'm thinking a 20th level mage could have something like 120 spell picks (stat +6 giving 7 picks times 17 feats). If this is not enough, consider using picks to by 'spell level slots' instead of just the additional use of a spell.
Comments?