1) I think you are right about the uniques. If you have a rare item or a blue one, you will be happy if you get a shitty unique. Sure, it might not be great or amazing, but you will be just a bit stronger.
2)I have mixed feelings on the stats page. I would honestly love to see everything,even the most unimportant stat, I find it interesting. You could add a short guide to the game explaining everything,you could make a "noob zone" where you can go and explain everything step by step,you can even add a difficulty(1. never played diablo 2.played it a while ago I know the basics 3. played median a while ago) . I don't know how you can define most important, or defensinve/ofensive however I think it can be done. Even if you use Defensive(hp,defense etc) Ofensive( dmg,attackrating,atackspeed) and both. Or you could use different names for them...IF you
you don't want to include everything,something like the offline tool would be cool. Even more amazing if you can make it real time, but it's not necessary. Basically the program could scan your save file and show your character ,stash and in depth stats(everything you can). You could also add any item from median,making it easy to experiment,finding out what stats you would have with that particular item. Don't know how this would work, it's just an idea
3)I think something like a library would be best, if you want to make the game more intuitive. Design an area of the map and put a lot of vendors that sell books and items. Have different zones for different stuff. You could make different levels so noobs don't feel overwhelmed and it would scale with the 3 difficulties of the game.However once you get a high level you can go anywhere on any difficulty. Giving items a lvl requirement for "buying" would make the message clear. You could add different rooms, for example, you are low level and curios about charms, you go into the charms room and there you can read what they are and how they work, then you can actually see a charm at the vendor and it's drop location. Same for any items and concepts, curious for an one handed axe runeword? simply go the the right library(normal/nighmare/hell) and you will see the item and the runewords needed in the shop. I this this would make the game much easier to process. If you make it extensive enough(add some simple guides,explain some skills,how synergy works and whatever noob or advanced concept you can think of)and there will be no need for the docs. If you plan it properly, it might be more enjoyable than the "dryness "of the docs