I think the embermage as a class is fine, but some of the changes synergies makes hurts them. I play as fire.
I'm pretty sure I was getting somewhere close to 450% extra magic damage from focus in vanilla with about 850 focus. The same amount of focus in synergies only gets me about 210% extra magic damage (ouch).
This wouldn't be so bad if I could slot %all-damage skulls and %fire-damage skulls to make up for the nerf to focus, but I'm practically required to slot 12 skulls of limoany (60% DR, + 15% DR from Immolation Aura for the 75% DR cap), and a good chunk of skulls of recheliu if I want to stay alive to deal any damage at all, which leaves precious little room for damage skulls/eyes. On top of this, I also need to use a shield (blech) for the extra slots it provides, and for the block chance which grants a 75% chance of me not going smoosh when things hit me.
To add to this, most of the high end gear I've found so far as been absolutely awful in comparison with gear I already have from vanilla, especially the burning blood set (transcendent and ascendant aren't much better, if at all. The only piece of transcendent I've found that has been an upgrade is the belt, but even that is primarily focus based, so it doesn't give me much.) I could go into depth about this (some of the peices are truly awful) but I'll give you the benefit of the doubt. I mean, it's called tier 0 for a reason, yes?
I've been grinding the troll areas in the hopes of finding this tier 0.5 fire focused gear I've read about, but haven't seen anything yet (in fact, haven't seen a single legendary from the trolls in 20+ clears).
As far as charge bar goes, what kind of changes where you thinking about? As a firemage, I gain charge incredibily quickly thanks to Blazing Pillars, Infernal Collapse, Magma Spears with just five points in charge mastery. In fact, I gain it so fast that I have full charge for more of a fight than I spend building charge. In light of the changes to focus, I could wish for a larger damage buff from having full charge, but that's about it.
I'm not sure what you mean by "static damage rates that did not increase compared to weapondamage rates". If you're talking about buffing current static damage values to be more inline with other changes you've made in the mod (such as the changes to focus), please do. If you mean converting current static damage abilities over to %weapondps... eh, I'm not so sure.
To give you an idea of the damage numbers I see...
Magma spears (51% weapon dps) hits for about 3-4k and 8k crits on the target dummy in table mountain. Once the dummy is burning, I start to get Fire Brand procs for 20-30-40k and 50-60k crits. Infernal Collapse is similar. 50-80k white damage with 100-130k crits. Add in Firestorm with the 48% increased fire damage taken, and I can see infernal collapse crits for as high as 200k or so, depending on charge bar status. Blazing Pillars is even more amazing. If I get all of my pillars on a target, I can see numbers as high as 400k (very briefly). Basically all of my big damage numbers are coming from static damage, so you can see why I would be apprehensive about any changes made to them.
If you're talking about an across board 5%-10% increase or something, that would be more than welcome, but without more information about what you would actually change, I can't offer much more input.
My gear isn't great, and I'm slowly weaning myself off focus heavy pieces which give my diddly squat in terms of %magic damage in exchange for good %fire damage peices, and my crit rate/crit damage is also somewhat low, so these numbers can only go up. (I should note that I've found precious few good %fire damage pieces).
I guess I would echo QuestionSign's post and say that survivability is my main concern over damage, at the moment, and that is largely gear based (which is frustrating for the previously mentioned reason of the tier0 gear being... of questionable worth.)