I have announced to myself this more than a couple times in my lifetime and I will probably say it again more than once.
I bought guns for the needs I had, most hunting, plinking, and defensive. I had everything that I needed for any conceivable purpose and I had the assets to buy whatever I wanted should a new need arise such as a hunting trip to Africa or Alaska.
Then I got hanging with friends who did the gunshow thing. I had never been to a gunshow. I thought buying and selling guns on a small scale might be a way to enjoy my hobby and hopefully eventually essentially have nothing in each of the firearms I owned. Didn't work. I bought more than I sold.... it was fun though, but I didn't make any money of consequence.
I discovered something important about my character.... I like guns more than I like shooting them. At least that is what it seems. I like nice tools, but I don't use them much ..... hmmm, collector..... sounds good.
Things change and I shoot more and I needed more shooters. So, if you truly believe you're done buying guns, more power to you. But based on your list, you haven't even started yet. Things change and your interests may change too.
Justin's suggestion was good. That is a great way to invigorate your interest and you will know after doing for a while IF you are really done buying guns.