At the last age change we were able to compare best offers to maximise the chance of buying techs, this time we will have to guess who will give best offer and try trading with them.
Why?
One thought I had is to gift all avail lux to the AIs we can trade with at least 20 turns before the age change (any time now), we allow the gift to continue until we have gifted them and they get their freebie tech.
Then whilst still in the big picture we cancel the lux deal (with no rep hit since more than 20 turns old ) and have multiple luxes avail for trade which we can get full tech price for via peace renegotiation.
The other advantage is with multiple luxes the AIs may have more money avail to fund our research (ie so we sell rather than gift techs)
At the next age change we require to trade for all 3 first tier techs (medicine, steam and nationalism) so that we get a second tier as our freebie (hopefully not ironclads or commie)
We need to turn "always renegotiate deals" off for that purpose, right? Or is it already?
I think it's worth a try. Much gain, no loss.
edit: Of course we raise the risk to get a trade route interrupted -
but once your reputation is ruined...
I suggest not trading any further optional techs (eg monarchy or chivalry) to scientific AIs to maximise our trading opportunities at that time
Of course after the worker(s) that are already scheduled - I just had not adjusted production to the plan this turn
Indeed, it is not that i want to completely line out the game for you, but i think the build orders i posted are pretty ok.
They are and I don't doubt them. But I think we should always validate them against the current situation which might afford some minor changes. Like the worker now builds in our core towns to keep science at 100%.
About the free luxes i don't know. Personally i think you guys have a little "fancyplaysyndrome" like we call it in poker. It may be cool to try all kinds of tricks, but often straightforward play will work just as well or better. I didn't like the idea to make wars between them without good reason, and i doubt this is gonna do any good for us either.
That's what I was thinking of when the bad news came in. However it was one of the few wars we did not ignite - but you are right, the risk of such a war beyond our control is tough to calculate.
Otoh if we cause local wars we migth lower the chance that those civs involved get different ideas like exploring the world with ships (and peer greedily at our weakly defended towns...).
Looking at the tourist commerce we get from the AT wonders - surprisingly also applicable for science - I think we should think about taking Istanbul too. HG and GW will provide some nice benefit. When we finished Portugal and Spain, we might ally Osman against Mayas or Incas (or both in that sequence), protect his Edrine heroically

and let them capture Istanbul.
I wonder how the flip risk would be if we "convert" its population quickly - Mayas or Incas would certainly help
downsizing Istanbul...