Interesting. I will let you know, as someone who has mostly second hand
Coach, and most of it Vintage, I have been all over the map with some of my pre-owned purchases. As was noted above, clearly part of my excitement for a used bag is the hunt (pouring through a gazillion listings), a bargain, the cleaning/rehab, an unexpected find of a HG type bag, recycling, you get the drift.
I have also bought several used bags in excellent condition (I swear they sat in a closet for 25-30 years) that needed virtually no cleaning or conditioning (I still vacuum them out and wipe them down with a cleaner and conditioner). One of them I was chomping at the bit to use, and did. Another , my black Plaza, had this slight universal fading , that nagged at me. And I am not a perfectionist by any means with my bags, but I was really disappointed when deep conditioning did not remedy it. I did get recolorant dye, restored it, and we are in love. Then there is my red Pocket Bag. It is gorgeous. If it was not for the barest pen mark inside, I would not think it ever used. So a basically unused red leather Coach bag circa 1990 would be admired by any vintage collector. But I did not immediately fall in love with it. I thought it would be a tad bigger. It seemed so plain! I couldn’t put my finger on it. And I had paid more for it than any other bag ($80, yeah I know some of you may be laughing). So I knew I could recoup that if I did not use it. But I decided to use it to see if I could bond with it over a few uses. I decided to date it, lol. Well, we dated and we are in love lol. She’s a keeper.
Nah, you’re not crazy. When you mention the strap not being the right length, it made me think of the fading of the Plaza. That nagged at me. Best of luck thinking on the bag. Perhaps like the above poster, pre-owned is not for you. Maybe you two should go out on a coffee date