I'll try and answer your questions, though I'm not that good of a player
(mostly because I don't have enough reliable free time for the long online games that is dominions
)
1) There was a thread for that once, though I have no idea how its called or where to find it.
Mostly the acronyms can be figured out easily, especially from context, and there aren't that many of them.
If you've got something specific to ask, you can just ask. (and you are right about SC)
2) Though I don't play online games, I know the most common mod online is the conceptual balance mod.
3) Dunno.
4) Generaly speaking:
Conjuration is summoning spells.
Alteration is buffs.
Evocation is damaging spells.
Construction is item forging + a bit of summoning.
Enchantment and Thaumaturgy are pretty much varied.
And Blood has lots of stuff but mainly summoning.
The easiest way IMO is to just check in-game.
5) Clams and Fever Fetishes produce magical gems, and therefore (especially with a hammer) quite easily exploitable (after X turns you completely repay your investment and being making gem profits, and en-masse you gain an infinite supply of gems. Clams especially so because they bring the versatile astral pearls, and those can also be used for chain casting Wish)
There are many other favored items, such as lucky coin, boots of quickness and jade armor, and many more.
6) To activate the blessing you need a Sacred unit, and a priest with Holy to cast Blessing on it to activate the power.
7) IIRC you get a commander for each 10 points of PD.
8) Theres a subforum for MP games, you can check there, or start your own novice games.
9) Everyone has their own strategy, but generaly speaking National units are only used at the very begining, later almost completely abandoned for summoned units (and the money used to fund as many mages as possible). Starting strats are varied, sometimes it is a good idea to go for easy to replace expendable troops and sometimes not, but are all aimed at having the best possible start in taking indies in order to prepare for war.
10) It is specific to each nation, and to each strategy.
A very high score in a single path is usually used for a strong bless rather than spells, and spreading your paths around is useful for site searching as well as being able to cast a wide variety of spells (and sometimes for an all-around bless), and SCs are useful for early expansion (as well as later expansion after a bit of equipment forging).
The rule is you should make your pretender fit your designed play strategy