Hi Juliette.
okay, I've not played puppet nightmares for a while, and up to now with Supernova not with nvda, but I've had a brief new look at the game (I love the new intro), and I think I can give some pointers here, hay I might come back and give things another go since I only got as far as episode 4 though I'll have to resist my urge to buy lesps), :D.
First, as to your question about items, last I played to give an npc an item in a quest all you need to do is go and talk to them with the key item in your inventory, that should do it.
Second, the most difficult thing in the game is creatures menu, though this is where you need to select a lot of actions.
One thing to bare in mind is clicking a creature's name will select it, while clicking a creature's stats will lead you to the information page about the creature.
A bit of experimenting reveals that the "report current navigator object" key, aka nvda numbpad 5 on the desktop will read you the mouseover information of what your focused on, so if your focused on the name of a creature, you can hit that to know about it's species, quality and type, ditto with other things in the game, this actually is a rather easier process than it used to be in supernova.
Lots of things work by headings which can make navigation easier, for example you can quickly browse through your creatures by hitting h, and when setting up parties the party main headings are level 4, but your creatures are level 5.
Other things can be found by clicking on parts of the screen, though you might want to use the quick navigation keys such as k for link, b for button and g for graphic to make life easier, eg, if you want to feed your creatures, go through with h and click on the ones you want to feed, then hit shift b until you find the "feed button", then hit c for the combo box to choose the type of meal you want.
hth.
As I said this is only what I found out with a quick ten minute poke around with nvda, but hopefully will be of some help.
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)