are all reasearch possible?
i mean can i play a game where i dont get buildings? can i play a game where i dont get military? can i play ONLY with magic? ONLY with adventure?
right now apparently you cant, you have to be a jack of all trades
lets see how this evolve
Right now that isn't really possible because of the way the system is setup. You need cities with lots of R&D buildings to get R&D done. I think they could add a few things to help decrease the need for the jack of all trades to let you earn R&D from other locations.
If you are playing the mostly Military route then the typical setup of you have a chance of getting their tech seems quite obvious. This is very common mechanic in 4x games. To make sure it favors the Military player more the percentage chance of taking a tech could be based off of their Military Tech Level. Thus players who focus on the other 4 trees won't have as high of a chance of getting a tech when the seize a city. And of course they already get more cities thus more R&D buildings from being heavily aggressive but this helps their R&D growth.
There is already a spell that increases your R&D output on the magic line but it seems to be rather low and easy to get. I think some other methods would be a nice addition as well that perhaps tie more into your magic level. I'm not sure if this kind of setup is possible under the current system but a unique building in the magic line that increases your R&D by a percentage based on your Magic Tech level. So if you have Magic level 10 that building would give you a 10% Boost to R&D in any city that it was built in. The exact % bonus and such would be an issue for balance but some mechanic that allows them to gather R&D other then Civics route.
Honestly I think the who Adventure route could use a little more work. But as far as someone taking the Adventure route while still having food R&D I think there are some ways this could be achieved. First off I think it would be nice to have tech rewards for goodie huts, ruins, and quest. Now a full tech might be a bit much but finding say a scroll that gives you X amount of R&D in either your current R&D field or one of the others at random could work. It would be nice to see R&D points carry over though as right now it sucks to being like 2 points away and your producing 40+ a turn knowing that 38 go to waste. That would only increase if your finding R&D scrolls that give you say 100 points and your only 2 away from level. Unless they are an item you can use when you want which could work very nicely.
Also the ability to perhaps recruit scholors which when they join you on a dungeon exploration increase your chance of getting an R&D reward. And perhaps your Adventuring level could increase the chance of getting something. That way pure adventurers are more likely to benefit from this unit's ability.
This one is kinda the hardest to play up because honestly it feels more like a side play style then a main one. I mean how many 4X games have you played where it's all about Diplomacy? Usually diplomacy is there just to do your relations with the other players while you focus on building your cities, raising armies, and doing research. And once you get the basic Peace and Trade treaties setup there isn't much left to do unless you wanna form an alliance down the road but even then mostly you spend your time minding your business while they mind theirs, unless of course a war breaks out.
That being said I'm not completely void of ideas on this part. First off I haven't really played with this tech tree much since there was no AI really to make treaties with until recently. But I know some games have, and I think I even recall seeing it listed in Elemental, the old Research Treaty. This of course would give you some extra R&D based on the R&D output of your empire and that of the other nation's empire. To really make it fair I think the smaller empire should get a larger bonus out of it because the larger empire already benefits from larger with more income. So if one empire produces 50 R&D and the other produces 100 R&D the larger one would get maybe an extra 5 and the small would get 10 thus their new totals would be 60 and 105.
Along with the treaty itself I think some tie in on the treaty's output for the diplomacy player should be tied to what level your Diplomacy tech is at. That way it again benefits people who specialize more and can't just be grabbed up by jack of all trade players which is how most unlockables in the tech system are setup now.
Also perhaps a unique building which increase your R&D based on the treaties you have setup in that city. So perhaps they generate 10% extra R&D you get from your trade treaties. Thus like in the previous example the small empire that produced 50 but was getting 10 extra from the treaty has maybe 5 cities each with this unique building then they would get an extra 50% from treaty thus bringing their total up from 60 R&D a turn to 65. Again the actually amounts would have to be something to figure out in balancing.
I haven't checked the Diplomacy tree in a while but I think some things that would go great in it would be Espionage type stuff. Perhaps some stealth units unique to the Diplomacy tree that can do all kinds of spy things including stealing tech points or full techs from the enemies would be a great way for the diplomacy tree to run R&D. Also the option to build Espionage type buildings that slowly steal R&D from enemies both that you have treaties with and hostile ones who refuse to engage in treaties.
As you may of noticed a bit of a reaccuring theme with some of the ideas is to tie the payout to the tech level. I think this is a very important setup because right now there does not seem to be much reason to specialize in something. It seems just grab what you need from that tech tree then move on to the others. After you got what you need just work on fluff items like the OP mentioned.
I feel there could be a lot more emphasis on making each of the paths not only feel truly unique but also make them viable options in their own right. Right now it seems like Civics is a must have and the others are just secondary choices, with the except of Diplomacy which feels like a last choice. So options to help with the Neutral factions could help develop it into it's own play style though, but again haven't looked at it lately.
I'd also like to sum up how I view each play style which may or may not fit with what the Devs have in mind but it's to help you know where I'm coming from how how I think they should be more "unique".
Civics (Economic Powerhouse Style): Few large cities, Lots of Production, Great defense, Lots of weak units supported by their massive economy
Military (Over whelming Force Style): Lots of Medium cities, Decent Production, Strong Offense, Medium amounts of fairly strong units, defense a bit lacking but countered by the fact they are usually the ones attacking.
Magic (Versatile specialist Style): This kinda depends on what spells the player researches along the way but because of that they can kinda change their focus quickly in terms of offensive, enhancement, summon, or etc spells. Mostly Medium cities though, Decent Production, Decent Offense/Defense (Depends on summons), can be very powerful with overland abilities.
Adventure (D&D Play Style): Few small cities, low production, few very powerful units, mainly earns money/resources/items from quest and raids, has some unique tricks up their sleeves with unique units. Also fairly heavily in recruiting mercs to fill out the ranks give their low unit amounts.
Diplomacy (Back room dealer Style): Even here on a what I think diplomacy style should be like I have trouble seeing it as a truly separate play style. I think the obvious friendly treaty options are there but also some back room espionage type stuff should be there as well kinda like in SoSE where you can bribe pirates to attack other players. That's because you still need something to build the back bone of your empire on. I mean what do you do for the first 100+ turns of the game if you don't find another player to work your unique abilities off of?