This is not symptomatic of a ground loop. Noise from ground loops would not stop when you touch the strings.
It sounds like you have bad ground on the guitar, which is totally different from a ground loop.
Ideally you should have 0 ohms resistance. A slight variation is ok. 30 ohms... you have to evaluate what is going on there. If you get that reading on the strings, it could be the plating on your bridge adding resistance or other factors. On the other hand, if you get 30 ohms resistance at the ground solder joint on the tremolo claw, you need fix that.
Resistance greater than 0 ohms could also indicate a weak, cold or degraded solder joint. This may be what is causing the 30 ohm reading on 1 pot. I recommend resoldering that joint.
As for why touching the guitar stops the buzz, yes it is because you have become the ground. That can be dangerous. Electricity follows the path of least resistance. If the resistance of your body is less than the resistance of your path to ground, electricity will happily seek continuity to ground through you. That is why you want resistance of 0 ohms or very close to it.
Using a multi-meter with a continuity test function you should be able to easily determine if/where you have grounding problem.
Plug a cable into your guitar jack and touch one multi meter lead to the sleeve of the jack then touch the other multimeter lead to each ground joint in the guitar, starting at the connection to the jack and working backwards through your system from there. You should have 0 ohm resistance (or really close to it) on your connections to ground.