Hi, I could use a little help.
I want to have an improvement that only the player will build and I’ve found that I don’t know what I’m doing with flavours. Also, what percent of shield cost is returned when you disband a unit in a city and can that percentage be increased?
I think the answer to the first question might be that you can only do so, if the human player will always be assigned to a single specific faction. Then by making the building require an untradeable, optional 'era-none' tech, then giving that tech only to the 'Human' faction you can make the improvement buildable by the Player, but no AI-Civs. If you want the Player to be able to choose which Civ they play, then obviously that solution's no good. However, AFAIK (from browsing the C&C forum, so this is not definitive), Flavours really only help to encourage or discourage the AI from
prioritising building an improvement, but they won't prevent it happening altogether.
The second question is easier: in the epic game, unit-disbands in towns always give 25% of the shield-cost back, rounded down (e.g. a disbanded Worker gives 2 shields, a Settler 7 shields, a Cavalry 20 shields, etc.). AFAIK (again!), that percentage is not changeable with the standard Editor (unless it's actually the inverse of the 'gold-cost per shield' for cash-rushing, i.e. 4 g per shield by default in the epic game).
In the epic game, the tech Recycling 'Enables recycling' (well, duh...) -- which I
believe is what triggers that you also get a gold-payment for unit-disbands -- and IIRC, that gold-payment's
also 25% of the shield-cost. So you could possibly get a little more bang for your disband-buck by giving a specific tech that attribute in your Mod. (Looking at the Editor, having a Recycling Center in a town doesn't seem to be necessary to give the gold-payment: the only flag checked for the RC is 'Reduces building pollution'; but if an RC
is needed for the gold-bonus, you could give the RC's flag to one of your buildings).