Quote: "wouldn't it also be helpful to see the name of the item you select in the editor "
That actually is shown in the bottom of the editor.
I've always liked the tree view as far as locating assets in the map. Works in everything else I've used. I wouldn't think it would be that hard to implement; it's pretty much a staple in windows. As far as keeping track of the overall inventory of assets (not just in the current map, I use an application called P3DO Explorer. I categorize everything into a structure like: "Favorites/Buildings/Valuable Assets/Buildings" or "Favorites/Bar Props/DVader/misc" etc. It's not a horrible system and it allows me to find everything relatively quickly and it doesn't change the original file structure.
EDIT: It's by no means the best solution, I'm sure, and it's kind of a pain to set up, and it won't prevent you from buying duplicates!
MAME Cab PC: i7 4770@3.4Ghz (passmark 9945), 12GB RAM, Win 10/64, GeForce GTX645 (passmark 1898); Shiny new laptop: i7 4800MQ@2.7Ghz (passmark 8586), 16GB RAM, Win 10/64, GeForce GTX870M (passmark 3598); Old laptop: i5@2.3Ghz, 8GB RAM, Win 7/64, Intel 3000 graphics