I'm using the wiki version as the base for my comments:
1) If you like Octopus Overlords' wonder, I'd suggest staying Octopus Overlords for long enough to get the wonder, then switching to another religion. Assuming that you like the Vampirism Feast ability, The Ashen Veil should be very tempting.
2) If you're going for Guardian of Nature, I'd suggest keeping a few Forests in each city (note that at least in theory, you can burn down Jungles, which will proceed to re-grow into Forests). Forests aren't too bad once you can build Lumbermill, and are significantly better with Guardian of Nature and Fellowship of Leaves. Alternatively, put nothing on a few tiles, for your Priests of Leaves to later populate with Forests.
3) Happy problems: my usual solution is just to build appropriate buildings (all possible Temples, Gambling House, Carnival, etc.) If I'm really expecting problems, I work on capturing animals very early - you can gain +6 happiness and a resource for 1 more from animals alone. Daladinn has some nice long-term happiness suggestions - I think his happiness strategy is detailed under the Kuriotates.
4) Each Vampire can summon a Skeleton; this should help in situations where Undead units are a bonus. Skeletons are also very expendable.
5) I note that you suggest that the lack of Elder Council is crippling. Here's an alternate suggestion: Build Villages, and keep your Research percentage high. The extra food from Agriculture isn't going to help you much until you have Vampiric units (and a substantial raise to your Happy cap.) anyway, and you can always destroy the Towns later, particularly when you have Aristocracy. Also, most cities won't initially be able to build Farms everywhere, and the loss of production hurts some on Plains tiles.
"We can not forget your cruel oppression."
You can switch the tiles you're working through the emphasis on your city. Myself, I virtually always build both until I'm ready to specialize (assuming that I do so).
PPPPPPPPPP
