Only for the leader in tech. It Does influence and speed up the Non tech leaders so the Whole global society is sped up, except for the isolated and rare AI/player, in terms of research achieved vs "date". Your analysis imhpo is backwards here.
But only the leader in tech should be counted for the date when a tech is achieved. That's the only way to get a true date measurement. So my point is that TD doesn't really influence the dates techs are acheived that much. Sure there's a little speedup, but fairly minimal. That's all I was trying to say.
Are you talking about Tech brokering or Tech trading?
Is not tech brokering only the ability to trade techs you didn't research yourself and thus only an option that makes any difference if tech trading is on? I am open to standing corrected here if I'm wrong. I'm really asking. I thought that was all it was.
The Dates will never be exact. That was proven long ago when Afforess took "Dates" out of AND2 while I was still part of that team. I used them as "Targets". Where the AI and normal players would reach a New Era by the research they could achieve by that Time/#of Turns.
This catering to the "elite" players just screws the H*** out of the game for any one else that wants to play the Mod. So when known Deity players come in and say I'm at X date and X Era I consider the exploits they Know how to use vs the Player and AI that has not gotten into that "method" of play.
I realize its an imperfect science, but shouldn't the dating be based on the best and most exploitive players to help players to guage themselves on how well they tend to achieve vs others? I've always felt that was, in essence, the point of the dates. If you are achieving before the real world dating for a tech, you can be assured you really know your stuff.
You stop expansion from happening and this Mod will turn into another version of CiV. The whole Civ series thru IV is about expansion. The Steam roll "issue" (which is only true for 1 segment of the players that play) is from trying to placate and pacify the Elite player. All other players do not suffer from this supposed "issue". And this is something I have fought against for Ages and thru many Mods. All game makers Must realize (and many do) that if you only target the elite your sales will be but a pittance of what they should be. So to get a game or a Mod to be widely used there has to be a broader appeal at the cost of putting some of the Elite Off because it's "Not hard enough". When in fact many of those elite that use this cry will Not self regulate themselves from using every exploit there is. So they clamor for "make it harder" all along not giving 1 thought what their desire and unbridled manipulations are doing to that game/mod for every one else that is not "up" to their level of play. And you will Never Ever satisfy the Elite player, ever.
There's a few elements here.
1) Our goal is to allow players to play a competitive game all the way through the Galactic era. If we allow for too much expansion too quickly, we must therefore then allow for maps to be much larger than our limits of data allow. Since we're up against some dissapointing limitations there, we must restrict growth and expansion.
Resistance to goal achievement is not a reason for a player to lose interest, it is a reason for the player to continue to maintain interest. Once a goal is obtained, the conflict to obtain it diffuses and the reason to continue to play is gone. So then you start over and you get better at getting to the goal faster.
I don't think we'll keep ANY players interested for long if we cannot get this mod to the point that it remains challenging throughout every single era, and not just from internal threats.
2) The difficulty levels should enable the game to be played by any player at any level, from the most lost beginner to the most seasoned veteran. Given that Vanilla achieved this goal, I know we can achieve it too. I don't begrudge the challenge to keep things interesting for the most advanced among us. Hell... that's OUR challenge that keeps things interesting for US! Even modding is a game in itself.
3) The steam roll issue has been clear to me with almost every single game I open. You know how many that is given how many games I have looked at to debug over the years. It is so very few that don't have thousands of points when their next nearest enemy has under 1k, a map full of civilizations all failing to even begin to keep up with the leader. This happens by Medieval usually. The steam roll is real and it's a big problem in this mod, if not one of the biggest. Obviously, AI is the BIGGEST contributor, but allowing nations to grow so much larger than their neighbors without penalizing them for it (which historically was tremendously perilous to a nation's well being - just look at what happened to Rome and the Mongols!) is also a major factor.
This game is not all that unlike Risk. Risk's biggest flaw is how terribly overwhelming the more achieving players become, making comebacks nearly impossible. Thus the second half of the game there feels much like the second half of the game here, primarily just taking time to mop up and officially end things. I'm not saying this is a unique problem to C2C. It's one of the underlying core issues with Civ in general.
I don't personally know how Civ V has tried to address it but it does sound like they tried. They can win a lot of battles on making things better but by moving to 1UPT, they ruined everything irrevocably to me.
Now that all that has been replied to (which I really did Not want to do,but did), I have been looking at some changes that would affect research rates by Era. So please don't get all wild about taking some of these "suggestions" posted here and making massive changes again until I have a chance to do some more testing and then submit these changes for overall usage. I'm working on a specific area, as I have done in the past, please don't throw a massive blanket over my efforts that drowns these efforts out, okay?
I have only been sharing opinions. I've no plan to work on this area of the mod myself.
My reference to CiV was from what I had read here at CFC in the CiV forum. I have never played any CiV in any form. Probably never will either unless I can buy it on sale for under $7. Yep that's how well I think of that Civ iteration. 
per turn was well above 50k for military units, and I'm fairly sure my capital alone was outproducing every other nation combined, in every category. I also had 300+ Great Military Instructors as the result of acquiring all seven base cultures, and effectively every religion and notable wonder. I'm just saying, that game is an absurd edge case in every way, the result of abusing just about everything I could without outright cheating, and really shouldn't be taken as a baseline for anything 
