I think your items 1 and 2 are a bit hard to take seriously but I congratulate you on 3 and 4. Nicely done.
I think saying that we're renting these devices is something like saying we don't own our ebooks. Of course we technically don't own the books so it's not exactly the same thing but it's close enough.
We have these devices temporarily. In a real rental we'd return them. In this situation we lose them when the batteries die. Both are temporary situations and a metaphor points out their commonality.
I really meant my post to be a humorous one. I seem to have hurt some feelings with it and if I did I'm sorry. I thought the term "rental" was used to express the posters feeling about the situation and that seemed fine with me and I wanted to gently mock those who didn't seem to get that.
Barry