I completely disagree with you on Wildfire. Namely because that would make it either extremely over powered or extremely useless unless you have a DoT heavy party. Also, since MCH only has one DoT ourselves, if it wasn't in the OP version, then we would be losing considerable damage potential without having to rely on other players to boost it. As is, my Wildfire after a full rotation is hitting for a little more than my most powerful attack, (Ricochet on a single target), and that's on top of all the damage I am doing to the target while it's up. The only way that I could reach that same damage level without relying on other party members to have their DoTs up, is if you did the full potential damage from my Lead Shot's DoT in a single burst. If you did that though, then in a party with even just a SMN and a SCH that threw up all their DoTs as well, you'd have a skill that once every 90s could put out close to 30k damage, (at iLevel 170, I'd hate to see the damage potential at 210 with a full party that keeps DoTs up, or even worse, a 24 man raid that does so). That's just game breaking. And as I said, if you had it as a percentage, even anything lower than 75% would lower the solo damage able to be done by a MCH using it. Meaning we would HAVE to rely on having party members who used their DoTs to their fullest if we even wanted to meet as much damage as we're doing now. That's a fine concept for when you run endgame content with a static that knows what they're doing, but for all of us who use the DF and small parties with friends, you'd be crippling us if you didn't make us damage dealing gods with that kind of change.......
For some damage numbers from my testing I was doing earlier, let me give you some examples.....
For point of reference, I was at iLevel 173, with no food, potion, or party buffs, purely using skill buffs. I'm rounding numbers here to make the math quicker and cleaner.....
Fully Buffed Ricochet - Average DPS was about 900 on the initial impact, with about 1800 on the distributed damage, giving me around 2700 if used on a single target, which is ideally the only time you use Ricochet.
Full Rotation on Wildfire - When Wildfire ended, I was getting at around 3000 damage, (give or take), after a full rotation. I have bad lag with my internet, so I effectively miss out on getting a basic attack or two in while Wildfire is up, so we could probably expect most players to get that closer to 3200 damage with my gear set up.
Already, you can see that 3200 is better than my most powerful single attack, which does 2700 without a crit. We could also expect the differences in these numbers to rise as I got things like food and my party DEX bonus, since Wildfire is based on what burst DPS you throw in, (all my skills, including Ricochet), while Ricochet is just a flat increase.....
Fully Buffed Lead Shot: I can't be 100% certain, but if I remember correctly from my testing, Lead Shot was hitting at around 400 damage every tick, (or every 3 secs), and it has a duration of 30 seconds. This means that with a fully buffed Lead Shot, I can effectively get in 4000 damage if it gets in a full 10 ticks while it's up.
If your proposed version of Wildfire does 100% of the damage of the DoTs on it, and I use it as soon as Lead Shot hits, then I could do 4000 damage with Wildfire, (probably actually closer to 3600, because one tick would likely be missed no matter what). This would put me higher than my current solo DPS with Wildfire. However, they can't just account for solo DPS, as they have to include party members. If they count for a full 8 player party with the potential for 4 SMNs, 2 SCHs, 1 MCH, and 1 Tank, (in single tank content), then suddenly that DPS coming from one player using one DoT changes into the potential for a lot of players using a lot of DoTs all at once. If they didn't put it at a low pecentage, then players could just throw up DoTs, have the MCH use Wildfire, and suddenly the boss would take a MASSIVE chunk of damage, on top of taking the same damage as the DoTs continued to tick down on their own, since as you pointed out, they would have to stay up to keep from ruining rotations. So let's say they did the percentage down on the damage Wildfire uses to what it currently is, at 25%. Well suddenly without having other party members' DoTs up, a MCH can only do 1000 potential points of damage with Wildfire. Considering that right now with no buffs up, (including no GB), and no crits, my basic Split Shot is hitting at about 600, then the fact that I could pass the potential solo DPS of a 90s cooldown skill with just two basic attacks is pretty sad. Particularly when you consider that doing those two basic attacks would take only a fraction of a second longer than doing the combo of Lead Shot > Wildfire.....
With the potency at any reasonable level, you'll barely be breaking even with the current damage Wildfire can do in a party that isn't designed around utilizing it. Meanwhile you'll also have to make sure that everyone refreshes their DoTs at the same time if you want the damage from it to be consistent from one use to the next. Also, as I keep saying, you'll be greatly hindering what we MCH can do solo if you make it so that one of our most powerful abilities requires us to have a solid party backing us up. In DF content in particular, you're lucky if everyone puts up DoTs to begin with, much less maintains them so that you can use a skill on them. The reason that we don't have skills that currently rely on other party members is because doing so means you can't use said skill without the rest of the party cooperating consistently, which means lower over all DPS....
As is, Wildfire is a big part of the MCH opening DPS burst rotation, and both from what I've experienced first hand, and from what I've heard, we have one of the highest, (if not the highest), opening damage rotations in the game. We are also quite capable with our average DPS if the player in question knows what they're doing, though we have to work a bit harder for it, and won't reach the same levels of over all damage as full DPS classes if the other player is equally capable. But, we also have support abilities that lets the group hit harder, or keep hitting for longer, if we choose to employ them. The players who look down on MCH tend to be the ones who judge how well a person is doing based purely on DPS, rather than what they're actually contributing to the run. Those types of players are more often than not the same ones who blame a wipe on "low DPS" even when it was due to a mechanic of the run that they themselves should have taken care of. I just ignore the people like that, because they're probably too busy watching their parsers to pay any attention to the logic you throw their way anyhow......
I'm sorry if I've come off as harsh OP, and I do understand that you mean well. Without playing the class though and seeing the way that the damage is implemented though, you can't judge a skill like Wildfire as needing to be completely reworked. It does what it's intended to do, and if used right, it does it quite well. I also appologize for repeating myself so often in my little rant here. It's a bit late, and I'm tired, but I felt the need to let you know why exactly you were wrong with your assessment, rather than just say "you're wrong" and go about my merry way......
EDIT: I'd also like to point out that this is just my assessment on the matter. I could be shouted down as wrong by all the other MCH out there for all I know. Still, as someone who fell in love with the class upon first trying it, I felt my opinion should be known, even if it's only that, "my opinion".....