I am also in the "care about DRM and probably wouldn't buy ebooks if there was no convenient way to get rid of DRMs" boat - I only came to the ebook world two years ago, and by that time I had already heard a lot of good about Calibre.
As for the book-hoarding phenomenon... I am not the big reader in my home; my wife is, and she won't read on an e-reader. And she doesn't ever re-read a book, yet we have lots and lots of filled bookshelves. Anyone who comes to visit is likely to leave with a book that my wife recommended - and we give away a few boxes of books to charity once in a while. Still, the very fact of being surrounded by paper books is something that seems to be important to my wife - and the possibility of sharing, either by lending or giving away the book once read; this is certainly a part of why she won't switch to electronic reading, together with the "feel" of a "real book".
As for myself, I'm more of a hoarder - my paper books are a tiny fraction of the collection at home, but I won't give them away (I re-read a lot more). I'll lend books I liked, but I expect them back some day
And I tend to do the same with ebooks now: I'd be upset if I couldn't keep my collection safe. Not sure why this is so, though.