like BR says:
your choices are
1. buy your books from Amazon (the ONLY legal seller of Kindle format books )
2. if buy in other formats from other sellers & convert/send to Kindle ( strange choice), then be prepared to make your own facebook entires, manually.
3. Amazon owe you only as much help as you are paying them for
4. A good epub reader will post your quotes to facebook, from the paid-for epub format, no hassle. Kobo, Sony.. have that facility.
5. hacking your book to fake Amazon into thinking you bought it from them , then using their social media add-ons, is a dangerous game - you'll have only yourself to blame if they blacklist your device & ban you for breach of their T&C
OK, that was my Easter exception to "don't feed the trolls" - shutting up now
