Hi! I'm a bit confused.
My first question is, is the maximum amount of layers 5, even with a GA?
Secondly, when I click any of the "Buy Layer" buttons, nothing happens even if it's not maxed out.

Without GA the max amount is 2, with GA is 3. You can purchase additional layers inside of the wardrobe. It should cost 75k (not that sure about the price) each layer and there should be a limit of 3 purchases each layer... any more bought just prolong the duration time.
But since the wardrobe is somehow broken again...
I see... so technically, since I am on GA time, my limit should be 6 at max (3 innate + 3 I can purchase potentially)? But since the wardrobe is broken, layers can't be bought anyway?
Yep, 6 max for GA. I just tried to buy layers. Got the message that I prolonged my face layer for 31 days... since I already had 6. With the chest layer I got "Congratulations! You've added 1 extra layer to your chest layer!" after hitting purchase. So purchasing should be possible.