Well, lot's here. I'll answer what I can.
TECH TREE
There is no tech tree. You access higher tier units with the relevant buildings. As your settlement increases in population stages (1-6, 7-9, 10+) you can upgrade the unit recruitment buildings you have to get higher tier units. As a consequence, city growth is vital, especially early in the game. You want to be growing to get those higher tier units, and to nab any wonders. The elves have a distinct advantage here as their cities increase in level with less population.
FAITH AND WEAVE
Faith is used to progress up the faith tree which unlocks various empire-wide and alignment-appropriate abilities, an alignmnent-specific wonder and additional heroes. Faith determines alignment (good, neutral, or evil) which in turn determines the religion-specific victory conditions. Good tends to favour growth, faith, and defence; neutral favours wealth and diplomacy; evil favours weave and conquest.
Weave is like culture in that it pops borders, but is also spent to progress up the various spell school trees, which in turn unlock various spells for your casters (both wizards, clerics, and druids).
Faith and weave are not zero sum. You can happily pursue both.
CHARTERS
You generate your own charters from the government building of large (pop 10+) settlements. You can also get them from various points on the faith tree, as a quest reward, or trade for them. For some reason other civs do not seem to value charters very highly, and many do not quickly expand even when they have unused charters, so it is usually easy to trade for them assuming reasonable relations. You can trade for a charter, settle a new city and subsequently let the trade lapse as the city will not cease to be because you lost the charter. However, this will put you into a charter a deficit. So, if you have 3 charters of your won, trade for 1 more, build a city and let the trade lapse, you will have 4 cities but -1 charters, so would need to generate or acquire 2 charters to build a 5th city.
RACES
Each race has a race-specific "promotion". Elves do better in forest, dwarves in hills etc. Race also determines what your basic units upgrade to. E.g. dwarves can upgrade a basic mounted unit to a giant eagle whereas other races would get some sort of rider.
CULTS
Cults spread like religions through undertaking quests for a cult centre (quick spread) or having trade links to a city where that cult is present (slow spread). Once a point of population in a city have adopted a cult they stick with it (barring loss of population). A city only adopts a city-wide cult if enough of its population follow one, so large cities with multiple cults are often not religious as no one cult becomes dominant there.
Different cults allow for the building of different clerics and shrines. Shrines just generate faith, but clerics vary in their strength and abilities according to their cult. Each cult also allows certain buildings to be purchased for faith points in cities that follow that cult.
I hope you find some of this helpful, but I've really only scratched the surface here.
