Realistic mode storyline and promotions while enlisted

[esjb]

Hello. So I decided to give this mod a try, it looks really cool! I am going to try to do the storyline at realistic gamemode so no quit whiteout saving but what will happen if I fail with a mission? Will I fail the entire storyline and have to create a new character? Also I noticed when I first started the game that my character is dirt poor and only has a shitty slow axe and no horse at the start, so I decided to try to enlist in Robbert Starks army, and try to make my way up in the ranks to get a decent income. But that lazy fuck almost never goes to battle! xD. I guess I have to join another lord who has fiefs closer to the border or something. It also took ages for me to get my first promotion in Robberts army so I wonder what is it that triggers the promotion? when I look at the xp needed or whatever it's called it says N/A but I still got promoted. Do I get promoted for amount of time being in the army, after a certain amount of battles thought or do I need to kill loads of enemys? Or what triggers the promotion?