I am thinking about building a temple in Trondheim (after an archer),
Please don't. Temples are full-price for the Vikings (60s -- which will take at least 10T to complete at 6SPT), and we won't actually need it any more once we're in Republic (with the commerce bonus), and have access to more Luxes. (Though, I'm not sure how Lanzelot figured we could make it to Republic in 20T, when we still have 19T on CoL, never mind Philo...?)
Admittedly, I haven't actually looked at Chox's save yet, but with 1 Lux already connected, all that river-CPT and LUX%=10%, and 2 military units in T'heim, surely we should be able to keep order in the town until at least Pop6? Remember, to prevent riots, all we need is for Happy citizens to outnumber unHappy ones -- so at Pop5, having 1 Happy, 3 Content, and 1 Unhappy is fine. And if you/we then build a Settler (30s), ideally timed to complete on growth to Pop6, that would not only be much cheaper than a Temple, but also solves the imminent unhappiness problem (at Pop5, with a half-full food-box, +2 FPT + 6 SPT, for 5T = growth to Pop6, and completion of 1 Settler, immediately dropping T'heim back to Pop4) -- not to mention increasing our GPT (and free-unit allowance) a couple of turns later, by allowing us to found another city (on my/ Lanzelot's purple spot).
That said though, if unHappiness is likely to become a problem already at Pop5, then we could perhaps think about making the 5th citizen into a Scientist, while completing the Settler (before we've built a Library, getting 3BPT for a couple of turns in exchange for losing 1-2 CPT and 2 FPT, may still be a better trade-off than sinking 60s into a Temple, and then paying 1 GPT maintenance on it until we dismantle it again, for which we only get 15 gold return).
1gpt in maintenance is slightly better than 1gpt per city per happy face from using the lux slider.
Not at this stage it isn't, it's exactly the same, because the 10% LUX%-setting won't affect Bergen (or any other newly founded town), while its CPT is still very low. Right now Bergen is getting, what, 4-5 uncorrupted CPT? 90% of 4-5 CPT = 3.5-3.6 BPT, which
should round up to 4 BPT (and zero Happyfaces, HPT) -- so running 90%SCI or 100%SCI will make no difference to Bergen's beaker-output. If you had to push LUX% to 20%, then yes, we would start losing BPT from Bergen in favour of HPT, but even then, it might still be preferable to building a Temple, because at least all our citizens would keep working.
Barbarians: The Arabs know wheel, does this mean we can expect horse barbarians soon?
AFAIK, it works like Barb-boats, which don't appear until someone (2 someones?) knows MapMaking: so Horse-barbs won't appear until someone (2 someones?) knows HbR. Barbs don't build Chariots!
I don't have enough experience with emperor level barbarians to judge whether we need spearmen in addition to archers.
The only difference that difficulty level makes is the unit-bonus against barbs (lower at higher levels). I can't remember exactly what bonus we get at Emp, but there is still a small advantage. Archers are better than Spears, since they can kill barbs before they arrive at the town gates. Barbs are set to 'Restless' for this game, IIRC.
Military: we are "weak" compared with our neighbors. If one of our neighbors demands writing, should we give in or refuse?
That's probably still partly because of their starting-units, but if Bergen is turning out vet-Warriors and -Archers, this shouldn't be an issue for much longer.
Remember also that (our) Warriors, attacking on the flat, have roughly the same chances of winning against (their) Archers as against (their) Warriors; and even with the Emp-AI's 20% production discount, we can still build new Warriors (10s, with no waste if carefully managed) faster than they can build more Archers (16s, likely with plenty of waste, because the AI
doesn't micromanage).
As for folding on demand, it would depend how far away the would-be extortionist was -- if it was the Arabs, I'd be less worried than if it was the Russians, because by the time the first Arab troops arrived at our borders, we would probably be able to kill a few of their units, then talk to their envoys and make peace again. In the meantime, a DoW would also give us War-Happiness.
But while there's still plenty of land to fill, you probably don't need to worry too much about potential DoWs...
In case of war with the Arabs or Russians, I would suggest an alliance with the other one & let them fight each other. This would mean selling writing to someone for cash to open an embassy, & writing for the alliance.
Building Embassies will make the AI-Civs friendlier, at least for a little while -- so it might be better if we did that
before anyone DoWs us! And if the worst comes to the worst, only one party needs to know Writing to form an alliance -- you don't have to sell it to the other guy, just like you don't have to know Navigation to trade maps with someone who already has that tech.
If you're absolutely strapped, and selling our tech-lead is the only way to make money, then OK -- but that really shouldn't be a decision made in desperation. Finding some barb-huts to smash for cash, would be far preferable (there's all that Tundra to the south of us for barb-farming...). After all, the AI-Civs can't make MAs against us until
after they have Writing/ Embassies...