OT ? ebooks, nooks, kindles et al

I used to have a sign in my office that said, in part, "We have studied the
question and have come up with questions at a higher level."
Me too.
I imagine I would like to have one of those. But there are so many
questions to consider. Such as, if I have a book on mine and want to share
it with my sister, can I?
Will my 'book' communicate with our public library? How in the Sam
Hill do you return a copy when the time's up?
I see that some of them come with ear pod somethings. Why would I need
them to read a book?
Just a personal problem, I expect, but I borrowed one from a friend, a
much older model ( the book, not the friend). I thought it was dim, slow
and heavy.
Are some models easier on old eyes? Are some easier for old brains?
Do you have one and have a ' I wish I could' list? Do you tolerate it
or love it? Polly