I've found there's a very wide range in desired as well as acceptable condition for previous season, secondary market bags. Of course any older bag in mint, never been carried, condition is going to be more valuable than one with imperfections but even bags with signs of use can find good second, or third homes.
I'm one of the collectors that likes my bags already broken-in, all slouchy and super soft to touch. If it has some minor marks then I'm less worried when I carry it and can relax and enjoy the fabulous leather. I have a very hard time using brand new bags.
Each leather bag has their own unique personality and character that develops with time and gentle use. As long as I wouldn't describe it as "thrashed" or "stinky" I can find some love for it.
Personally I don't care if the tassels are cut, my S/S '02 Chocolate First has shorties, but I don't like if they look like a puppy chewed on them and rolled them in dirt. The hardware is designed to look antiqued (except for the giant hardware) and I think any oxidation or natural polishing is totally fine along with minor scratches.
Rubbing that's minor doesn't bother me and light fingernail scratches aren't a big deal. As for color variation it gives the bag a more vintage look and as long as it's a natural thing and not b/c of too much direct sun or bright light exposure which would make the bag look weird.
Darkened handles can vary greatly from barely noticeable, just the undersides to nearly black all over which is more than I can handle [LOL!] I don't mind some patina but prefer when it blends well enough not to be overly noticeable.
So that's my 2 cents on the subject ;o)