Welcome to Basenotes, MJMoonwalker. Glad to have you around talking about fragrances with us.
Your question comes up frequently with new members, and you're sure to find a great amount of posts on the subject if you'll type your subject line into the subject line.
Judging from the information in your post I don't think you're running any risk of having your scents go bad before you use them up or become tired of them. Keeping them in boxes protects them from light.
Years ago I wrote up the following post because this topic comes up with the frequency that it does. Maybe this will further explain:
Yes, fragrances can go bad. Emphasis on the word “can,” though.
But how long before they do? Five years? Ten years? More? Less? What’s average? It all depends.
Fragrances go bad because time, heat, oxygen exposure, and sunlight change the oils that make them up. Standard advice for a long life of a bottle is to keep it in a dark, cool place--a closet, say. Sunlight changes wood, paint, rugs, and most things it blasts. It will change the fragrancy of oils too. Heat likewise. Further advice is to buy spray bottles in the first place because they have smaller exposure to air--capped bottles get opened every time you use them. I read on Basenotes that pros have special refrigerators to keep scent archives in.
For me the hard thing has been knowing when one of mine has gone bad. I wonder if my nose has changed, gotten used to the scent, or gotten the taste for something else instead--as if the problem is not in the older bottle. The ones I have decided were bad turned kind of blah, and had no really distinct notes like they used to, or, I think, start to have one strange and powerful odd scent that jumps out at you too quickly. For example, I have to go smell a new bottle of Drakkar Noir to see if my old bottle has gone bad. My old bottle seems to have a sticky, strong peppery scent when I spray it and it doesn't seem like anything I want to wear even if just for a day to see if it's bad. I remember getting to like Drakkar after it was on me for an hour or so too. Whether my Drakkar is good or bad doesn't really matter now, when I smell the bottle I don't want to wear it. That's the standard to follow for your fragrances. Very highly citrus scents might have a shorter life, since citrus is short-lived and breaks down easily while on the skin at least. My Eau Sauvage and Chanel For Men were the first bottles that I ever wondered if they’d gone bad, but touches of each seem fine on the skin after a half-hour. Those bottles are over twenty years old.
Proper care of fragrances is a real bummer. What's the use of the beautiful bottles and nicely colored liquids if you have to keep them in a closet?