Channeling is a game about a group of people who are among the small group of mortals who can gather and harness power. Not in the sense of political or social power, but a more tangible spiritual power. The power can be used to perform supernatural feats, from incredible feats of strength or agility, to fireballs and lightning bolts. Right now i'm trying to hammer out exactly how this works... i was told that a short story format might help people figure out what i was aiming for, so here it is, a short scene of a magical fight (with very vague mechanics, and a few that i'm not sure about including, but the basics are there) of use. Gathering still has some work to do before i figure it out enough to do so.
~
Saareth crouched behind a rocky outcropping, watching the man he was hunting recline against a tree. He was alone... perfect... Saareth slowly moved over to get a line of sight, and began chanting quietly to himself, an outstretched finger tracing a glowing rune in the air, taking his time to etch it perfectly, before releasing the rune, focusing his power through through it to send a lightning bolt towards the resting man. The bolt slammed into him, shattering the decoy into scraps of cloth and straw.
Cursing, Saareth jumped up and spun around, just in time to see the man swinging a sword towards him. With a cry, the channeler fell back, and threw his hand out unleashing a blast of fireball, unrestrained by rune magic. The spell worked, and the man was engulfed in flame, but Saareth felt something snap within him. The wild spell had cost him, and he wasn't sure if it was worth it.
~
Alright now for the outlined mechanics...

Gathering Power
My current idea with this is to allow characters to collect "sparks" of power. These sparks would be present in living things constantly, allowing easy access. Sparks could also be gathered from certain other sources or actions, such as a sacred grove, or an explosion. They would be gathered through a specific skill/attribute roll, and stored for future use. Exact mechanics? Feh, i havn't even gotten a firm idea of the idea, never mind the mechanics yet.

Using Power
Power is used to perform supernatural feats, including feats of skill and spells. It's use is difficult, due to the fact that it was not intended for mortals to use. Using power is a multiple step project. First, the player rolls to check if he manages to access the power. Failure means nothing else happens, success he goes on to the next step (this step is an idea, may discard due to too long casting mechanic). Afterward, the player rolls to see if they maintain control. Failure means that the spell goes out of control. Depending on how bad they fail it could be something like just missing, reduced effect, to things like draining the players power pool, backfiring, or permanently destroying dice. Next, the player  rolls the actual attack/spell, trying to hit/effect the target. On this roll, depending on how the spell is cast, specific rolls may have specific effects. A 1 on a die may destroy that chunk of power, a max roll may allow them to reroll, (or also destroy the die). FINALLY they get to roll damage. I understand this is a slow mechanic. The way i intend special abilities are to be common enough to happen a couple times each fight, but few people will use them every round, or even every other round.

Casting Methods (possible idea)
This may be adding unneeded complications, but considering having 2-3 different ways of casting spells. If i do, they would be Runic, Wild Magic, and (possibly) Ritualistic. They would be three steps on a scale of speed versus risk. Ritualistic would take a long time to cast a spell, but give bonuses on activating the power, and maintaing control. Wild Magic would be very quick, but stand a good chance of negative effects (the idea above about dice dying on minimum or maximum would be Wild Magic). Runic would be the balance, taking less time than Ritualistic, but less chance of risk than Wild. Runic and Wild were in the short scene above.

Questions
Now the specific questions...
1) Just, overall, any obvious holes i'm missing?
2) Is the first roll in casting worth the time? Or should i just count on the control roll to serve a similar purpose?
3) Is the casting methods too complicated?
4) Any other suggestiongs not mentioned in the questions you think would help?

Anything i'm missing, just post, and i'll respond as soon as i can.

The system seems to emphasize the theme that combat is unpredictable and dangerous and power is often more trouble than it's worth. This means that combat-heavy games that use this system will give the players a sense of helplessness. This isn't necessarily bad, but you should give the players some kind of alternative to using power like this, either "safer" mundane fighting or advanced options for non-combat interaction.

Another question: If you use the idea of the initial roll, would anything keep a character from trying again immediately after? Do you want chaarcters to wait for an indeterminate amount of time to get their powers to work?

Also, is there any way to consolidate all the dice-rolling? Try breaking down all the things that might happen to a character who tries to use a power (success, backfire, permanent harm, temporary delay, etc.) and deciding how likely you want each outcome to be.

There will be plenty of non-power abilities and such. Standard combat and non-mystical skills will be fine, and hopefully good enough to make it at least possible to play a character without power (although no suggested). Also, i hope to balance out the powers so that they are, at least a lot of the time, worth the risk.

If you use the idea of the initial roll, would anything keep a character from trying again immediately after? Do you want chaarcters to wait for an indeterminate amount of time to get their powers to work?

Also, is there any way to consolidate all the dice-rolling? Try breaking down all the things that might happen to a character who tries to use a power (success, backfire, permanent harm, temporary delay, etc.) and deciding how likely you want each outcome to be.

(my apologies if it's frowned upon to revive threads that had slipped off the front page, especially if they are your own, but i had some new ideas, this isn't just a bump)

Alright... i'm afraid i may need to retract some of this thread, (maybe all of it?) but i hope i can keep some... I like it, but i realize the mechanic i was replacing was most of what defined the game... so i don't want to take it out.
The original mechanic went as such. Instead of the building up a pool of power from various sources, the channeler drew power from a single being, one from a different plane of existance. This being was bound to the channeler through a ritual (though could be released to allow for another one). The casting system involved beating the demon in a conflict resolution (havn't exactly decided yet) to allow the power to be taken. Each channeler also had a mana-style stat, that went down with use of powers, but represented instead the amount of control the channeler had over the being. As the level of control went down, the demon began to be able to influence the abilities being drawn from it, and at lower levels, even the channeler and surrounding area/people through the opening the channeler used to draw the power. At a certain number, the character either had gross changes or else in some way becomes unplayable (warped beyond use, death, catatonia...).
I love the mechanic presented in the above posts, but the mechanic here was part of what i designed the game and setting around (well, not the specific mechanic, but the idea). A way to combine them would be good though... perhaps have the demon's skills be represented by pools, and allow the player to add to it through the above ideas? or allow the player to build up small pools of power themselves so they don't need to use the demon for smaller spells?
Any other ideas?