The iron grip of the FIRST ORDER has spread to the farthest reaches of the galaxy. Only a few scattered planets remain unoccupied. Traitorous acts are punishable by death. Determined to suffocate a growing unrest, Supreme Leader KYLO REN has silenced all communication between neighboring systems. Led by GENERAL LEIA ORGANA, the Resistance has planned a secret mission to prevent their annihilation and forge a path to freedom…
-- The film would have been called "Duel of the Fates"
-- Finn and Rose are given lots to do. They head to Coruscant to light a beacon at the old Jedi Temple to signal the galaxy to war against the First Order. From there they steal an old Star Destroyer and are captured and sent to a POW camp. Finn connects with a old Stromtrooper friend and together he and Rose led an uprising with other Stormtroopers in the final battle on the ground while Poe fights in the sky.
-- Turns out Kylo killed Rey parents. She isn't related to Palpatine at all (he isn't even in the film). The force ghosts of Luke, Yoda, and Obi-Wan assist Rey against Kylo and they try to bring Ben back to the light but its unsuccessful and he dies.
-- Leia isn't as featured as much. The script was turned in before Carrie passed. While there were stories about there being a version of the script where Leia fights Kylo, this isn't it.
-- In the end, Finn and Rose take force sensitive children (including broom boy from TLJ) to a remote planet so Rey can train them as the new generation of Jedi.