TranquilSilence
Grumpy Snufkin
I don't know if it's codeable yet, but I imagine it would work similar to how Austria and Venice do their thing. Balance-wise, it's just a matter of fine-tuning the rate of city conversion.
I presume it wouldn't be too different from JFD's S-P/Italy UA, so it should be possible enough. That said, I have little to no knowledge of actual code.
Also, yeah I'd be up for doing the Pedias, at least for the UU and the UB, though at first glance I couldn't find much regarding the Zenata in the context of Granada itself. If I can find some good sources I'll eventually do the Civ and leader pedias unless anyone else wants to cover them.