Balin and Dwalin would have probably taken the lead with which ever brother, Fili or Kili, was next in line being the Heir. They probably would have made more intellegant moves as Balin would have accepted the aid of Thranduil. Fili/Kili, as King would have most likely honored their word and paid out to lake town and they would have been a more unified front when the Orcs came instead of two armies scattered and fighting one another.
a Hobbit wrote:
Another question is what of thorin lived? Would he replace gimli, March the armies of the dwarves to pellanor fields ETC.....
Book: Would a living Thorin have resisted the tempation of the Dwarven Rings as offered by the Mouth of Sauron? If he took the Rings he would sit in his mountain and watch the other nations around him burn while he sat with his rings and counting the new riches gifted to him by Sauron for taking the offer. If he did resist then Erebor would still have been under siege as it had been with Dain ruling. Without being able to break the siege he wouldn't have had the resources to march south. He also had no friendship with Gondor nor did Gondor pay him to bring an army (Tolkien himself speaks of the mercenary aspects of Dwarves who would have forged weapons for Melkior if trade had been opened up between them; also, barring those who were members of the Longbeards [who had a long standing friendship with the Elves], Dwarves fought on both sides in the Last Alliance).
In Peej's movies I don't know what motivation Thorin would have had to come south with an army. Thorin was a selfserving, short sighted fool and would probably be counting his money rather than march to the aid of some humans he doesn't know. I doubt Gimli would have meant enough to him for him to march an entire army south for him alone. He would have been more likely to march to Khazadum to avenge the loss of Balin and the Dwarves there then to go to the aid of Gondor. To me the Movie Thorin was an even bigger fool then the book Thorin.