After getting to know the animal over a longer period of time you'll be able to tell the difference of a 'relaxed s-neck' and a 'aggressive s-neck' just by the body language of the animal.

You really should leave the snake alone for a week (or until it starts feeding regularly for you) and not handle it. It's still accumulating to it's new enclosure and will be nervous.

Also, I suggest trashing that heat lamp and getting a thermostat controlled UTH.