Sterling, switching the boxes is following their nature, especially if you want to enhance brood rearing.
i have never opened a wall to see that the bees have switched the position of the comb. neither have i opened one and found that the bees have built comb upward.
yes, you probably jumped the gun on adding another box but you don't say what size boxes you are using. if they are mediums, you are ok with what you did. if they are deeps, check what buzzbee posted. he pretty much covered it.
bees build comb down and move back up into the top of the boxes as winter comes. they fill the combs from top down with food, that's why you put honey supers on top. also, the queen will not often cross honey, so if the box you have on has lots of honey/syrup stored and you put a new box over it, she probably will not move up to lay. you can fix that by pulling a couple of the frames up into the new box and replacing them with empty frames. that gives her a way to go up.
it is my preference to put new boxes under.
it's a little harder to watch what's going on in the new box when you put it under, but most of the time you can check it by pulling some frames from the top box and looking down into the bottom with a flashlight. most of what you need to know, you will see that way.
feeding: the only way to know if you need to feed is to get in there and look. the idea that they won't take it if they don't need it is bunk. they will take it and they will fill up the brood nest. then they'll swarm on you for sure. if you look and you see that they are filling up with syrup STOP FEEDING. same when there is a flow on. you have to check and get room in there before it becomes a crisis.