Modding AC questions

[zerocold]

Is there a way to avoid some factions to get specific units or techs?, for example i don't want the caretakers can get planet burster, or let the mindworms only to gaians and the cult, the alien spores por the cult only , more agressive mindworms for the cultists, and so on

Also, i wonder if i can design speciphic units/abilities por factions, lets see, a plane with more (or less) range for an specific faction

Thanks