I think that's solid. It'll save you a lot of grind time for actual teams to run the dungeon and I had wished I done it sooner myself. I also feel like going heavy on provisions and having one or two cow slots is what you want to do early. The extra items really help with keeping teams alive. Also, getting kennels for more missions makes it easier to get the levels you want or to go gear hunting.
For everything else, just open them as you need them. You shouldn't really need more then one or two slots in most buildings unless you are going for instant use later in the game. I personally found I never really relied on Morale or the Seedbed stuff that often for example. But it also can be nice to be able to remove an annoying trait or hypnosis mantra on your good units.
