I'm doing the Renegade's Mission with Madanach. But wtf??!!!!????!!! I don't follow the story line anymore...
I'm rp-ing a good nord ok? So i'm a stormcloack, but now i get caught in this mission and i have to side with Madanach who is against the Nords (they did awful things to them). I'm getting confused... i want to rp a good character, it's seems impossibile... any help?

Nope, this is simply a bad, bad questline. You're railroaded into doing questionable stuff (assuming you just don't try to kill everybody on principal, if that's even possible) and on top of that, there's no real consequences to any of it. I ran into old Madanach at his new hideout, and he had nothing new to say. All of his buddies also spammed the same line over and over.

Feels poorly thought-out and unfinished, overall.

*points to the no spoilers sticky* you really didnt see that?

You must be new to the intarwebz, so I'll give you a hint. The word "Sticky" is potent magicks that makes all threads within it's range invisible.

Just in case any PC user got the delightful looped dialogue from the guards after those quests: http://www.gamesas.com/index.php?/topic/1276340-cannot-get-rid-of-bountin-malkrath/page__view__findpost__p__19309006

I really thought you were gonna comment on the looping guard dialogue. Worst bug I've encountered in Skyrim.

You can just kill him and escape by yourself... Think of it as of siding with the nords. You still get a reward.

I did the right thing.

I used Madranoch and his gang to help me escape, and once we had escaped I slaughtered the lot of them in front of people of Markarth, so that everyone would know who saved them from the King in Rags.

If you go that route be careful they are all pretty badass, but the fight is epic if you start jumping from walkway to walkway, in the river, and just generally running all over Markarth to keep them from surrounding and killing you.