OK i have put up a beta version (v1.2.4) with your 99% of your suggestion in place.
The changes were only to the NP_CODE.JS code library so this is all that needs changed is you have already used the code in an application of your own.
The changes are these
(1) The First item on the selection list is "Selected" by default so once the name gets to the top of the list you need only press and this will duplicate the double click select of that item
If you do this on the Multiple Selector it will add it to the selected list
(2) If while typing you use the or keys the focus will change to the selected list
and you can navigate it using these keys. Pressing while doing this does the same as (1)
(3) I having quite got the event model to be the way I want it in IE yet so when you key the first time this moves the focus to the select list, but does not move the selection bar down. Pressing again makes the selection bar move down one.
(4) Pressing when on the selection list will not take you back onto the input object .. so to start typing again you will need to click on the input field to give it back the focus.
I will have a look at the event propagation to see if can get around issue (3) and (4)
Hope this is what you where after
This is basically for all different forms of the NAB picker. I would expect that if I type part of a name and the name I want appears on top of the list, an "enter" would choose that name. Now I have to use both keyboard and mouse to select a name, which is a hassle. It would also be nice if you could scroll through the list with the cursor keys.