I've read 56 books in the app this year, all manually uploaded with full metadata. I can even confirm most of the books I have read show up in the Book store as well because I am annoyingly suggested to buy them whenever I try to find them in 'search' (annoying feature)
The review doesn't show up in my app but someone below thinks their uploaded titles have been tracked. Who knows what the rhyme or reason is.
In my experience Apple Music Replay is terrible so my expectations are measured anyway but I would like to be able to use this service if it were possible.
I agree with all of your other points and I'm not trying to convince you to switch to Apple Books but you actually can airdrop books between devices! Most of the time I don't need to because I sync my whole library over icloud but occasionally I will download a single epub and then airdrop it to my ipad and it imports immediately.
I'm otherwise not picky about the rest of the things (my biggest gripe is actually poorly imported metadata! and I've finally gotten Books to show all my cover art so I can't switch now) but the Airdrop ability is a must for me and I use it a lot.