Ok so these might not be true but I think they might be.
1. Dustpelt and Ravenpaw are littermates
2. Honeyfern was pregnant with Berrynose's kits when she died ( Unsure but maybe its true )
3. Bluestar's name was going to be Moonstone
4. Brokenstar has kittypet blood.
5. Firestar and Graystripe are related - Bluestar's mate was Oakheart whose brother was Crookedstar.whose kit was Silverstream. Silverstream's mate was Graystripe whose mother was Willowpelt. Willowpelt's kits are Rainwhisker, Sootfur, and Sorreltail. Sorreltail and Brackenfur's children are Honeyfern, Poppyfrost, Lilyheart, Cinderheart, and Molepaw. Cinderheart's mate is Lionblaze whose mother is Leafpool whose father is Firestar. Simple!
6. Hawkfrost may have loved Ivypool.
7. Tigerclaw's name was going to be Hammerclaw
8. Rosepetal and Foxleap were going to be mates, until they decided they were to closely related and so they killed off Foxleap.
( I'll add more later )