You're killing me here! I try to answer in a clear way! Anyways, you said:
Do you want the reader to click a link that will simply show them stats and inventory for each NPC? How are the NPCs going to get items in their inventory?
And here's the answers: Yes, I want them to see the NPC's stats and inventory (I'll figure out a way for the reader to understand it isn't their inventory), and NPCs will start with some items. They then could be given items at their specific page, and would also pick items up in parts of the story. You wouldn't get the items that they get, unless you choose to swap it for another item (also done on their page, via links).
Is that enough information? No? Then here: you also said this:
Do you want the reader to have a single item that represents each NPC and then they can use that item that will then show them the inventory of that NPC and be able to use items from there? I can't imagine how that will work in combat unless you only allow a single NPC to attack each round, if you wanted the reader to select actions for each NPC, that might get pretty complex.
No, I don't want a single item for each character. I have an item made called a Census that will end up bringing you to the party page, where there are your party members. Combat rounds won't work out, but non-traditional combat will be where the NPCs use their items. And yes, I'm aiming for a complex story.
do you want the reader to be able to switch between different NPCs, "See" through that NPC's eyes, and have their inventory change to only what that NPC has? If so, how is that going to work (by using an item(s)?)
Technically no, no, and yes, in that order. You can't switch between being a player, but they can switch between who's stats they're seeing. No, you can't "see" through the NPC's eyes (unless you have a certain item, but I haven't given that any thought until now. Maybe a Sight Crystal or something, to see what you don't notice, but the NPC's do?) And yes, the player should see the NPC's inventory. Happy now?