denugis:

I find it intriguing that Soulless!Sam was not where Sam keeps his anger.

I think it would be interesting, though not an obvious extrapolation of canon, if Hell!Sam were.

Hmm. Here’s some random speculation in response:  

IIRC, the soulless in Supernatural after Sam would primarily get angry or aggressive when they weren’t getting something that they want.  You have to have a decently developed sense of self to 1. identify what you want, 2. Get ticked when you don’t get it, and, most importantly, 3. be able to delay gratification enough to control your aggressive impulses and direct your frustration into more adaptive means of expression or problem-solving.  

If soullessness means disabling #3, then you’re left with #1 and #2.

But Sam’s self was predicated on hunting. He and his family were already well trained to sacrifice large parts of core aspects of the self in the service of hunting.  Loss of self was immaterial, then, because the hunting remains.  The “rules” of hunting as determined by the culture of his family would give him guidance in all things, just like Donatello used Mr. Rogers as his guide.  Which, would then make sense of why having Dean around just “made things better,” for no specific reason that soulless!Sam could articulate.