I really like the OP's ideas for feats. Feat choice paralysis is something that spoils the game for me, and I'd really rather have either a much simpler list of feats that provide static bonuses or extras, or just do away with them all together.
Examples of good feats are: a +2 bonus to fire damage, or a bonus to saves vs fire for a fire mage; a +1 to accuracy with light blades for a rogue; heavy armour training for a barbarian; an extra healing surge etc. You should be able to look at feats and say "I can tell what kind of person that is" (so things that fit the flavour), rather than "I can see how that character might approach a fight" (which is the optimisation angle).
I know it might sound boring, but I feel the flavour of the character should come from the way you play it, not because you've chained up a list of odd options that make the character situationally good.
Those might be good things, but they cannot really be good in the same category.
+1 accuracy in a 4e type system is about a 10% boost to your offensive abilities if you can trigger it constantly.
A bonus to saves vs. fire -- it would have to be near-immunity, because unlike the other things, you have
no control over if you are fighting a fire opponent or not.
+2 bonus to fire damage means that your character is going to either be strong if they choose all-fire powers and avoid fire-resistant monsters (which, of course, is not under your PCs control), or weak if they end up splitting their damage over multiple kinds (because the feat is now pretty sub-par).
Heavy armor as a barbarian could be on par -- what it does is it frees up the Barbarians secondary stat from mattering to the Barbarian's AC in 4e. That could have huge, or tiny, design implications. (it now takes 3 feats to hit plate as a barbarian, and 15 con or so.)
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The "Expertise" feats from the essentials look like better feats along these lines. Some boring (yet powerful) static bonus, and then a flavourful minor conditional bonus.
"
Fire Mage Specialization: Gain a +1 feat bonus to damage per tier with arcane power damage rolls, and +1d6 fire damage per tier on a critical hit with all arcane powers. When you use a power with the fire keyword, you instead have a +2 feat bonus per tier to your damage rolls."
You'll see that the above feat is many-fold. It rewards you for using fire spells with an extra +1 damage/tier. It gives you fire crit damage, turning even your non-fire spells into fire damage. It also grants you a
baseline damage/power boost, that applies in every situation. Cold Mage Specialization might look quite similar (except it slows on a crit instead of +1d6 damage, immobilizing if the target is already slowed).
Wand Expertise: You gain a +1 feat bonus to accuracy per tier when using a wand. Once per attack while using a wand when you roll a natural 1 on an attack roll, you may reroll the attack roll. When attacking a creature you hit last round, you ignore cover and concealment (but not superior cover/concealment) when using a wand.
Here we have an expertise feat. It has the large static bonus effect, plus a few flavorful riders. Here, I split the element bonus-to-damage feats from the tool bonus-to-accuracy feats.
Ideally we'd do the same with martial powers -- have keywords on powers that we key off our damage-bonus feats, and keywords on weapons we key off our accuracy-bonus feats.
The point is to avoid "you get a +1 bonus to some number that will always apply, and nothing else" feats: balancing those feats against situational feats is nearly impossible. Either players who like situational/flavourful feats are screwed because the boring feats are optimal, or the players who like the boring feats are screwed because the situational feats open up a world of "cheese" that breaks the game.
By having both in each feat -- both a boring boost, and a situational thing -- you can have a non-trivial power upgrade from the feat (from the boring boost), and something interesting (the situational feature of the feat).
