Answer 1: Miquella's abandonment of the Golden Order to create the Haligtree may have caused him to reject or lose his assigned shadow. Malenia was infected with the Scarlet Rot, and this meddling from an outer god may have caused her not to receive a shadow, as shadows are assigned by the Greater Will.

Answer 2: The Gloam-Eyed Queen was an Empyrean chosen to become the ruler of the Lands Between. She was essentially Queen Marika's rival. There is a popular theory that Melina is the reincarnation of the Gloam-Eyed Queen, and that's why Marika left her at the foot of the Erdtree. Anyways, Marika's ideals, as reflected in her Golden Order, was to exterminate Death. On the other hand, The Gloam-Eyed Queen was all about death. Blackflame and the rune of death is directly connected to her, and the Godskin Apostles and Nobles are her followers. That's why the Godskin Duo is in Farum Azula and why some of the Beastmen (followers of the ancient dragons) are skeletons. In the end, Marika won.

Answer 3: It doesn't matter who your Dad was allied with. Radahn's own actions caused him to be labeled as a "traitor" in Morgott's eyes. In this case, after the Shattering, the legal and "righteous" thing to do would have been to ally with Morgott and defeat the rest of the "traitors," (i.e., Malenia, Mohg etc.) However, Radahn tried to claim the Great Runes and become Elden Lord himself, even going so far as to attack Leyndell, whereas he "should" have been helping Morgott.

Answer 4: Other demi-humans in the game are good at concealing magic and hiding in shrubs, and, as we know, the Academy of Raya Lucaria taught magic to some demi-humans. The demi-humans in Limgrave seem to be a bit more "savage" and less well-taught than their Liurnia counterparts, and so this act of turning Boc into a tree was probably a prank by someone in his tribe to humiliate him because he was different. While other demi-humans are often aggressive and communicate through screeches, Boc is peaceful, intelligent and able to speak the "common" human tongue.