This kind of thing has been discussed before in great detail, though I don't know how much has actually come of it. Check the Ed Depot scripts indeed, and also have a really good hunt around the forum, going back quite a while if needs be. Search on things like "enhanced AI".
AI units cover each other and you automatically - I suspect setbehaviour combat works best but don't quote me. It doesn't work very well in enclosed spaces like villages.
OFP is a great game, but it has strengths and weaknesses. Buildings are one of the weaknesses, which makes it an attractive area to try and improve but also one where improvement is most difficult.