Thamewolf's page

Interesting catch, ShaperMC! As I argued above, I don't think the Magical Knack trait is even necessary in order to get some limited use from it, but Magical Knack may offset the limitations you'd have.

Magical Knack:
Pick a class when you gain this trait—your caster level in that class gains a +2 trait bonus as long as this bonus doesn’t increase your caster level higher than your current Hit Dice.

My concern would be that it says "pick a class," not a class ability. Thus, while you would not break the "as long as this bonus doesn't increase your caster level higher than your current HD" rule with Channel Energy, you would break it with every other feature or ability.

Still, the trait doesn't say you can't take the trait if it would increase your CL such, just that you only get the bonus if it doesn't increase your CL past your current HD. So it could be argued that this trait just has no effect until it goes to check for Channel Energy and suddenly your CL becomes lower than your HD. Unsure if that works or not.

I'm going to give a try at arguing this, based on the language of the rules. First of all, unless you want to houserule it, there's no way I could see arguing for this to affect spontaneous conversion (though I totally think that should be its own feat). While your choice between the two abilities must be the same, Channel Energy is not listed as a "prerequisite" of Spontaneous Conversion. They both refer back to each other.

On the other matter though, I think a good argument can be made from Channel Energy's text.

"The amount of damage dealt or healed is equal to 1d6 points of damage plus 1d6 points of damage for every two cleric levels beyond 1st (2d6 at 3rd, 3d6 at 5th, and so on)."

There is nothing in that statement that says it cannot be used at effective level 0. The only thing that would suggest that would be the chart, but obviously for convenience sake the chart would not list such a thing and in general the text is the actual rules and the chart just a guide. The base is quite explicitly 1d6 and the only thing levels effect is the "plus" for every two levels beyond first. For the secondary channel, however, it would remain 1d6 until 5th level.

Also, the DC for the secondary channel:
"The DC of this save is equal to 10 + 1/2 the cleric's level + the cleric's Charisma modifier."
would remain simply 10+CHA until 4th level.

That all seems fair to me. It's a feat after all, and feats can do some powerful things if used properly. I think an extremely stunted (and often half damage due to the DC) channeling attack or a healing channel that's multiple levels behind is plenty balanced for a feat.