Thats a lot if text in one spot... My '86 NA2T Z31 is running fine, not in limp mode, without the idle controls. They certainly are not needed.
Also, when using a Z31 ECU these days, a good thing to consider might be Nistune, stock turbo Z31 injectors are 260cc so you MIGHT be able to get away with 295cc, but i can't say you would for sure