ok, tech trading seems weird all throughout history. What's the reason for this? It seems the AI values their techs at the displayed beakers while my offers are valued at "time it takes to research x their beaker production" (thus including the usually very high research boni).
And Byzantium....well they suck. I mean, now that I know that there will be a plague around the Arab start I managed to play until meeting the first UHV without any major trouble (Sinope and Aleppo joined my Empire something like 3-4 times^^). The western barbs are...well there to train your troops for the Bulgarians it seems, they never pose any threat, while the ones in the east are not much more than a nuisance once you reached the Arab start and made peace with them. It might take a good chunk of your empire to produce units to counter them but once your walls stand....meh.
And then...out of the blue there appear the Seljuks with dozens of incredibly strong units within my borders. Yeay. Reload some old save or lose 4-5 cities -.-
It would be really, really good to have some sort of warning, like I suggested with Poland ("There are rumors of hordes of a strong and advanced tribe that is marching towards you, coming from the east.")
Because right now Byzantium is just annoying, you have to play it once just to know what events there are to cripple you and then you can play it again to prepare. I'd also recommend some sort of info either in the screen where you chose your civ or at the starting info for Byzantium that this civ is not recommended for players unfamiliar with RFCE.
It's not that playing with Byzantium is especially hard or anything. At 1050 I had twice the score of the next best civ and held Damascus + my whole starting empire (except for Jerusalem and the other city that usually flips to the Arabs - I led the barbs burn it down in 550

). It's just a game I find to be incredibly annoying. I know this probably sounds harsh and you put a lot of effort in it, in order to translate all the historic events into ingame-action, it's just...it all happens without any warnings and while there is some randomness to it, the events are pretty consistent, favouring people who have played the Arabs/Byzantese/Bulgarians in RFCE before a lot over "Newbies" and most other players.
Since Byzantium starts the game as THE main power I think most people new to RFC want to start with them (at least I did) and might get too frustrated to try any of the "more-fun-for-beginners"-civs.
-> Again: Please think about adding some sort of warning/info for Byzantium.
edit: yeah, if you know what to expect it can be sort of fun. I went 2 turns back to 1068 and spent 1k gold and now that I knew they would come 2-3 turns later it wasn't as frustrating.