After you have a chance to play a game or so, please check back here and give your impressions on what was to powerful, and what you may have just avoided for being to weak.
Holidays are over, finally played a game with each civ at least once (multiple games with Sidar, Svartalfar), my observations and opinions so far:
powerful stuff:
a)Farms + Specialists.
Except for playing one of the elf factions this just beats any Cottage, workshop or sucky windmills out there. Especially after getting Guilds.
How about changing, say the Serfdorm civic to something like "workshops +1

+1

instead of the +20%

it got right now ?
Cottages could be improved by giving an underused civic choice (like mercantilism? dunno if that makes sense in an historical context) +1

and prolly +1

for towns.
This would at least bring them up to vanilla civ 4 level - and its not that great in vanilla either.
Instead of pushing the other improvements you could also try to make farms worse: +1

per farm (is that possible/codable ?) would still allow them to be an extraordinaire food source if used sparsely, but kinda make GP-farm-cities abit harder to build.
Thi would also improve the need for

in FFH, which is kinda irrelevant right now. (more details down below)
b)Fire mana
Archmages + Fire 3 + some protecting units = quite hard to stop.
Heck, its that good that I tried to get 3 fire mana nodes with every civ using magics I played after discovering it...
How about reducing the coll. damage from metors or at least reducing the numbers of meteors you get per cast ?
c)The grigori world spell.
Wow....just wow... see a)
d) Guardian of nature:
I know it requires a whole tech and a certain state religion and it just works with the elves.... But +15

still obsoletes quite every other building and resource giving happyness.
How about changing it to +1

just for Ancient forests ? Or is there a way to make it 1/3

for Forests, jungles and Ancient forests ?
e) Forges:
Kinda build them in 80-100% of all my cities, the factor and time just depending what civ I played. +25%

is just too good and there are quite no alternatives.
Additionally you even get +1

whe nyou have gold....
Thats nice but kinda a no-brainer to build.
How about lowering the

-bonus or adding more

(2 or 3) to forges to make the decision abit harder.
f) The great library:
It's a cheap wonder (just 350

), the prerequistes aren't that harsh (even as a non-builder-faction you normally build a few libraries to boost your research) and the rewards are just breathtaking. I tried to build it with every faction I played.
I really like the idea that it boosts the

of Scientist specialists (and Scientist GP), but right now it provides quite alot of beakers just by itself AND get you a great scientist in no time, even further raising your beakers, especially as it's benefits als apply to the free Sages you get....
How about lowering the free Sages you get to 1 (instead of 2) ?