I’ll try to get up to speed in one post, then ease off a bit. First, I like the mix of ideas in general.
Energy Admixture/Energy Substitution/Energy Gestalt/ Energy Specialization: This group whispers Paragon Path to me, too. Perhaps it gives away too much to put all of these powers out on the table in a grab-bag fashion. I’d rather see an Energy Master Paragon Path that melds these into a coherent, themed specialty. Your mileage may vary.
Idea, Energy Scholar (Heroic)
Prerequisites: Wizard, at least one power with an energy keyword.
Benefit: Choose an energy type (Acid, Cold, Fire, Lightning, or Thunder). Any power you use with an energy keyword from this list will use your chosen energy instead. Your attack rolls with the chosen energy have a +1 bonus.
Special: You cannot take this feat if you have the Energy Substitution feat. You may not use other energy types from this list unless you take the Energy Master Paragon Path.
(This is strictly a theme-based specialization feat so we can have pyromancers, frost mages, etc. The narrowing of the caster’s versatility in converting most damage to one energy form makes this a Heroic Tier power, IMO.)
(One spin would be to list all 10 damage types instead of just the energies, as a "Specialty Scholar" feat (Poison Mage, anyone?). However, this might make the resulting character too much of a "one-trick pony". Thoughts?)
Enlarged Burst/Reach: Buffing individual effects seems a design dead end to me. I don’t think there is enough bang for the buck for this practice, since a character only has 18 feats in a whole career. I would prefer to see combined, themed packages instead. For example, the following might be worth a look:
Idea, Overchannel (Wizard only) (Paragon):
Prerequisites: Intelligence 17, Constitution 15
Benefit: Once per day, you can substitute the Overchannel feat power for one of your daily powers.
Overchannel
Daily + Arcane, Attack Implement
Stance + Standard Action Personal
Trigger: In your turn, you use a move action to ready yourself and a standard action to use a healing surge to power this effect.
Effect: For the duration of this encounter, all your powers with a range greater than Close gain a +5 power bonus to range, all your powers with a burst effect gain a +1 power bonus to their radius, and all your powers with variable damage deal a power bonus of +2 to each die of damage.
Special: The instant you use your final encounter power, you must make a saving throw vs. unconsciousness. If you fail, the Overchannel power ends immediately and you fall unconscious. The encounter power functions normally, regardless.
(consider: Epic Special: At 21st level, range increases +10,
bursts increase +2, and damage increases to +3.)
(The non-blue special might be too fiddly, but may give players an interesting choice—do I use a more powerful encounter power and risk putting myself down, or do I use weaker at-will powers and hope the opponent drops first. What if party powers have a really sweet synergy with the encounter power?)
Greater Cleave/Magic Missile Mastery: These seem OK at first glance. I’m just unsure why they were configured as feats instead of higher level attack powers.
Magic Missile Mastery (2): My group has a wizard who finds it impossible to hit with magic missile. We’ve had a 9-10 sizable encounters and he has yet to hit anything(!) with the power. It’s embarrassing the rest of us. He desperately wants some sort of “magic missile mastery”, but in his case, a Reliable version, or an auto-hit feat would be more appropriate.
((There is some local rumbling about everything in 4e being so dice-based it’s too dice-based--some players here have been subject to Epic dice-lice infestations.))
Hideous Blow: No comment at this time.
Sacrificial Blast: Don’t like the name, which sounds like a paladin/cleric feat. “Infernal Blast” might be better.
Seeking Missile: Seems a bit fiddly. Why not just give combat advantage when shooting at an opponent in cover?
Equilibrant Savant: This looks like a divine form of Energy Substitution, so the tier peg seems right.
Great Commander's Strike: At first read, looks pretty solid to me.
Heavy Priest’s Shield: (Not crazy about the name.)
Do you get the bonuses if the prayer attack misses? If you intend no, then the wording might be improved:
“If you hit while using your Priest’s Shield at-will prayer, the prayer AC and Reflex bonuses are +2 instead of +1.”
OOPS! MISSED ONE
Desperate Accuracy: This feat poaches the Elven Accuracy racial power. I would be reluctant to make racial abilities generally available this early in the game’s life—the races would lose some of their “cool”-factor before the audience could even get used to them. I’d shelve this for a year, then look at it again.
I do have a suggestion for a feat template based on the word “Desperate”.
Triple Strike: I would like this better as a Desperation feat (see below). An additional attack is one of the most highly leveraged bonuses in the game, IMO. This one may be unbalanced as written.
NEW IDEA
“Desperate” Feat Template: Desperate feats deplete healing surges to power cinematic special abilities -- in short, the player is putting all chips on the table and this move should be high risk. “Desperate” feats have all of these characteristics: Triggered when you are bloodied, powered by one or more personal healing surges, the effect replaces a daily power use, and the feat is once/day, nonrechargeable. Ideally, the consequences of failure when using the feat should have the player sweating bullets.
And that's a wrap!