I personally use an Android e-ink device (that you can't buy anymore). I know, I know ... hear me out.
It has very old version of Android, where I installed a very simple Nook Touch Launcher and a few reading apps. All I ever use on it is AlReader (not aireader, but alreader) reader that has support for e-ink screens. All other apps on it suck. The only time I am outside AlReader interface is when I have to restart it, or when battery dies and it starts up again. I find myself in a launcher and start AlReader immediately. There is nothing else to do on it, just read. You choose the book to read from within the AlReader app.
AlReader is available as a free download and supports Android 1.6 and up.
http://www.alreader.com/?lang=en
So, if you do not find the ideal e-ink reader, there is always an option of installing that on an Android one and forgetting there is other stuff available.
I do not use collections, AlReader can browse hierarchical directories and I always make a "catalog" of all books I load on the reader using Calibre.