I'd surely like some help with the xml, but before I'll go about recruiting volunteers, I'll need to do two things:
1) (and I'll probably do this tonight or tomorrow) is to compile my own version of the DLL with plenty of debugging statements (I saw that betterai already has a tech debug logging system in place, and that'll make my job a lot easier). I need to figure out what kind of values actually do make sense, because evidently those ranges have changed from vanilla (where a value under 1000 made the AI just very slightly more likely to research a certain tech while a value over 10,000 practically forced the AI to research the tech as soon as it could; this time round I've had techs with values of over 20,000 sitting there unresearched for the longest time. I have some theories as to why this is)
2) I need to come up (with xanaqui's help) with a plan of things that we actually want to accomplish with the xml, short-term and long-term. I anticipate that these will be quite different things, and that the short-term goals will be very temporary (as in, emulate a certain kind of behavior until it's in the C++ code) and as such potentially frustrating (why go to all that trouble only to have your work removed in a few iterations anyway?). We'll need to come up with some sort of scheme that makes our short-term work as useful as possible for long-term goals (such as some sort of semantic tagging of techs to substitute/extend the AI's valuing of them: for instance, instead of looking at the units that IRON_WORKING grants and deciding based on that information that it's a pretty valuable tech for anyone going for the MELEE branch, the AI could look at IRON_WORKING's FLAVOR_MELEE tag and based on that come to the same conclusion. At this point I'm not at all sure if this sort of semantic tagging will help at all; in a perfect world, the AI should be able to gather all this from the game itself, which would lead to a much more dynamic system and save us from having to adjust flavor tags every time there's a major balancing change in FFH)
To give you some perspective, in the beginning I didn't really think I could accomplish anything but disabling the magic tree using the XML. I've made some progress toward minor goals at first (teaching Calabim to go for Feudalism, for instance, and Luchuirp to beeline Construction). Then I made those civs that lack a certain branch of the military tree (like the Khazad, who lack any archery units beyond the dwarven slinger) avoid those techs. Finally I realized that I could maybe emulate some of the things that we will eventually want to put into the xml, like encouraging the AI to concentrate on ONE military branch (since branching out in FfH is almost always handicapping yourself; for more details see
http://civ4wiki.com/wiki/index.php/FfH_New_AI_XML). This is way suboptimal: the same leader will always prefer the same path (predictable equals weak) and he will not be able to react to a changing environment (enemy pumping axemen with shock? Maybe research Bowyers rather than Iron Working). So this last part I fully expect to remove again once we have that in the C++ code. However, I've become attached to the idea of giving more flavor to the leaders--the dwarves heavily preferring melee, the elves going archery or recon, and so on--and I believe that some of that will be used lateron when we have a logic in place that'll make the leaders choose one kind of military strategy early on. Also I think that the flavors on techs can be useful once we have a sort of leader-chooses-strategy-and-sticks-with-it logic in place since the capabilities of the AI to look at a tech and decide how useful it is for a certain strategy can be less than perfect. I imagine a hybrid system where the base value of a tech for a certain strategy comes out of the flavor attached to that tech, but on top of that the AI adds contextual information, like this: both Celerity and Precision are good last tier archery techs, but the enemy we're currently at war with is using low strength but dangerous units (assassins? mages, if the AI can ever use them?) protected by stronger units that aren't as dangerous, so we should go for Precision rather than celerity. (this is WAY off in the future, btw).
Uhm. Rambling too much. In short: yes, I'd love any kind of help with the xml, but we're not quite there yet. Don't wanna waste your time. If you'd like to help us plan stuff, you're more than welcome. I'll setup sth on the wiki soon.