thanks for playing!
1) yes, it is possible but a bit difficult, though it does not lead to much else other than extra dialogue because it is mostly leftover content from an earlier period in development that i didn't want to scrap. maybe someday i'll patch the game to make it a bit more substantial.
2) also yes! i haven't made a walkthrough for the fourth ending in lieu of keeping some mystery alive, but i leave some hints for it at the very bottom of the official guide page.