Yes, he did. Erin hunter revealed in an online chat on wandsandworlds.com that both Firestar and Scourge had the same father, thus making them half-brothers. Firestar killed Scourge in the last book of the first series.
No, he will not.
Yes, because Firestar is Scourge's half- brother, and Firestar and Princess are brother and sister.
His two daughters are Squirrelflight and leafpool (daughters of firestar and sandstorm). Firestar does not have a half-son but he has a half-brother who is scourge (because they have th same father jake).
No, Firestar has no way of knowing that he is related to Scourge.
Brambleclaw kills his half-brother, Hawkfrost, in self-defense during a battle. Hawkfrost had betrayed ThunderClan and threatened Brambleclaw's life, forcing Brambleclaw to kill him to protect himself and his clanmates.
Scourge is Firestar's half brother, along with Princess, and confirmed by Erin Hunter. They all have the same father, Jake, a ginger kittypet mentioned in Bluestar's Prophacy. Also, in the Scourge comics, Quince mentions that none of her kits had his ginger fur.
No. He does not.
No, she killed Ashfur and she's dead now, so I don't think she will kill Firestar.
Firestar's kin are: His sister, Princess His nephew, Cloudtail His two daughters, Squirrelflight and Leafpool His five grandchildren, Hollyleaf, Lionblaze, Jayfeather, His nephew's daughter, Whitewing His nephew's daughter's two kits, Dovepaw and Ivypaw His half brother Scrooge
Yes, Firestar's unknown faith mated quince making scourge,socks and ruby firestar's half siblings
Ashfur
No, Tigerstar does not kill Firestar in Omen of the Stars. Firestar dies under different circumstances unrelated to Tigerstar. Tigerstar's actions continue to affect the Clans, but he does not play a direct role in Firestar's death during Omen of the Stars.