Unfortunately liner notes are not always as explicit as you'd like, so sometimes you will end up collecting them all just so you can listen and ensure yourself of any differences, then eliminate the duplicates from there.
As for "And I Love Her," this is the same six riff rendition as heard on The Alternate Hard Day's Night and the Rarities LP. Some of these takes are hardly significant and only last a few seconds, but again I guess that would be up to the listener to determine its value. It may take some keen ears to really hear the difference in sound, that's partially why quality does have its importance, but often the results end up being the same take being tweaked and experimented with by bootleggers.
Some collectors will go out on and endless search for everything, when in reality, they already have everything. But there's always this 'incomplete' feeling and need they have to run through everything to make sure that truly have it all, and they still need a little more. I personally find it to be a waste of time and space when there's so much more out there to experience. As I said, it all comes down to the listener's peak of satisfaction and when they have finally reached it.
"The best argument against democracy is a five-minute conversation with the average voter."-Winston Churchill