Also do most people do 30 coats of tru-oil on the neck or does this have a thinner layer compared to the body ?
When it comes to Tru Oil, I think there are as many methods as there are people applying it.
Depending on what you want to achieve will determine how much or how little you apply, and where. You can do just enough on the neck to seal the timber, but you may find it needs to be re-applied occasionally to keep it protected (depending on how much you play it).

My builds (1 body and multiple necks) that have a Tru Oil finish have a minimum of 24 coats (more likely 28-30) but that's because I wanted a good glossy look and I like the feel of the necks with that level of finish.
I've seen many builds here and elsewhere that go as high as 50. I just lack the patience to take it that far.