A bit in between, really. Perfectly willing and even eager to deal honestly with others, until they crossed the line or stabbed me in the back.
The Khans have already proven themselves to be enemies and were destroyed to the last. Letting them escape Boulder was a tactical act of mercy to safeguard the lives of the NCR soldiers there, and nothing but. "Merciful Thug" my ass. The Khans are just as much scum as the Legion and worth as just as much consideration. Wipe them out and move on to something actually worthwhile.
The Brotherhood may be a pack of short sighted morons, but they're skilled and heavily armed morons. Peace is brokered for the greater good and because really, the BoS in the Mojave is a paper tiger. They don't have the ability to stand up to a focused assault, so the NCR may as well put themselves in the position to make use of the BoS so long as they're willing to deal. If they step out of line, Moore gets a new BoS bunker to make an outpost out of. Going for a peaceful settlement risks nothing, and gains a potent ally for the time being.
Recusing the soldiers in Nelson is a no-brainier. They swore the oath, so their comrades had dammed well be willing to go to the wall for them. The Ranger that calls for the murder of the hostages deserves to be stripped of his rank and dishonorably discharged in total disgrace.