UPDATE MovementRates SET
TotalTime = 0.5 * TotalTime,
EaseIn = 0.5 * EaseIn,
EaseOut = 0.5 * EaseOut,
IndividualOffset = 0.5 * IndividualOffset,
RowOffset = 0.5 * RowOffset;
in my version, I've moved Research Agreements further down the tech tree, as some other mods have done. Tech progress is still way too fast, IMO, not giving enough time to enjoy Classical and Med eras.
This is an interesting idea. It would slow the game down - almost always a good thing - and probably feel more realistic as well. (Although I assume other mods have delayed RA's appearing because they have more of an impact than VEM's diluted version.)
I'm currently playing with Research Agreements becoming available with Archaeology, following Darkhour's realism mod and seeming consistent with the creation of an international academic system in the 19th century. This slows tech down for early and mid-game, but lets all players invest money (which they have more of) later on when tech progress becomes more expensive and historically tech moves forward in leaps and bounds. I'd still make Research Agreements more expensive if I knew how, though, to reflect the larger sums of money players have to throw around in this mod.
I lean towards an option C, a science-only benefit, because of the goals for peaceful-tall empires in the three playstyles thread. This science focus is the same reason RAs strongly favor peaceful empires in vem, with the 50% declaration of friendship bonus. It gives peaceful players a technological advantage to counter militaristic players' army advantage.
I think these thresholds are the reason people feel getting happiness isn't important. The only direct benefit of stacking large amounts of happiness is slightly faster golden ages, which is not enough, as you pointed out before.
This is why I like to use a direct 1-to-1 approach for rewards. I think it would improve things if each point of happiness gives an immediate, tangible benefit. I left the thresholds in place because most of that code is in the game core only Firaxis has access to.