Almost -- entAng needs to be the player's actual angle (and not just a representation of it), since that will get directly changed by the function. That is:
alignToVec(my.pan, vec, vector(0, 0, 1), 1); // you got vec right, as well

Also, to smooth things out, you might want to have the last parameter be time_step.

What this will do is align your model to the normal by its local z axis by changing its orientation as little as possible -- so really, whatever your model's previous angle was will determine the direction it is ultimately facing. Then you can use ang_add/ang_rotate (I always forget which one) afterwards if you want to change the ship's pan relative to its current orientation.

It'll make more sense as you put it into practice and fiddle with it, I think.

The planet generator looks really cool