Where Did Robb Stark Go Wrong?

If Ned Stark's flaw was his unwillingness to "play the Game of Thrones," what was Robb's flaw?  Youth?  Inexperience?  Breaking his vows?  Entrusting the wrong people?  Or making bad strategic decisions?

There were the immediate causes of the Red Wedding:  breaking his vows with the Frey's and marrying for love, trusting Bolton, his decision to march on Casterly Rock, but there were other strategic elements that brought him to the point where the walls closed in.  Let us look at those:

1.  The decision to raise banners in the first place when his father was taken hostage.  Verdict:  Good decision, one he needed to do.

2.  Continuing to march on Tywin Lannister when his father was killed and not recognizing Joffery as king.  Verdict:  Good decision, follows the same logic of the first decision and resulted in the capture of the Kingslayer.

3.  Acceding to his bannerman's call for him to become King of the North.  Verdict: Huge mistake.  At the time, this was awesome, but in hindsight, seems to be a mistake.  What had Robb done to warrant being a King?  Had he not learned the lesson of Robert Baratheon - the difference between winning wars and ruling?  Why not support Stannis' claim to the throne, continuing Ned's policy, and trap the Lannisters between two powerful enemies?  He would have gotten his father's justice and restored Westeros to basically the same state it existed prior to Ned becoming the Hand.  Perhaps Robb's flaw was arrogance?

4.  Sending Theon to get Iron Island support.  Verdict:  Small mistake.  Robb needed to do this once he declared himself King of the North.  BUT...he could have done it differently.  He could have demanded Iron Island support -- rather than ask -- and not entrusted Theon.  He had no reason to distrust Theon at this point, but he did have reason to distrust Balon.  This was a tough call and Robb had not been let down by his bannermen or people around him yet, so it was a forgivable mistake, but a mistake still.  The lesson:  do not give unproven allies the benefit of the doubt.  Make them "pay first" by demonstrating loyalty before giving them help.  He should have kept Theon as a ward until the Iron Islands successfully attacked the Lannisters and the war was over or settled.

5.  Not torturing Lannister prisoners and generally treating them well.  Verdict:  Basically a good decision.  Robb theorized that treating prisoners well would encourage the Lannisters to do the same.  They did not.  This pissed off both of Robb's main bannermen and sowed later seeds for betrayal.  But, I don't think this was a mistake.  Getting into the gutter would not have changed the overall calculus of winning the war.

6.  Breaking his vows to Frey and marrying for love.  Verdict:  Obvious mistake.  Definitely the most clear mistake, but perhaps not his biggest.  I think declaring as King of the North was still the biggest because he lost sight of his original goal: justice for his father by crushing the Lannisters .

7.  Not punishing his mother for letting the Kingslayer go free.  Verdict:  Good decision.  What's a guy to do?  This was not a mistake, although it sowed doubt in the minds of his bannermen and gave them major frustration.  But honestly, what was he going to do?  Kill his own mom?  No choice here.

8.  Continuing to march on the Lannisters after Theon took Winterfell and the Kingslayer was free.  Verdict:  Mistake.  Robb considered going back North and retaking Winterfell, but was talked out of it by Bolton because they had the Lannisters on the run.  This was a mistake.  This is like when a gambler is losing and starts betting more to "win it back."  You need to stop when the signs are flashing red.  Losing the Kingslayer and losing Winterfell were signs Robb was losing his grip on power.  Yes, he was winning battles, but he was also "losing the war."  Plowing forward was the first desperate move he made.  It turns out Bolton may have been manipulating Robb at this point, but we are not sure yet.

9.  Going back to ask Frey for help.  Verdict:  Obvious mistake.  Another compounded mistake, like sending Theon to the Iron Islands.

In my mind, the mistakes break into two sets:  strategic mistakes and tactical mistakes.  The strategic mistakes were the more costly:

a.  Declaring self King of the North
b.  Continue to fight war after Winterfall fell and they lost the Kingslayer
c.  Breaking the marriage vow with the Frey's

Tactical mistakes:

a.  Going back to Frey
b.  Sending Theon to Iron Islands

I'm sure I am missing some stuff.  I might expand this into a real piece.