The Essential Nature would say no to that. The shape a a human body is part of it's essential nature (ArM 79). You could move the eyes to their backside but they would go back. Same with fingers and toes and legs and limbs.
I think the ship would leave the earth over turned. You could make the size of the effect a bit larger than the boat so that it lasted a little longer and then the earth would flow back ( like water). It would still leave a track as moving boulders and trees aside would not move back. If you have ever read Elric of Melniboné ( Michael Moorcock) there is a ship like this and it's effect is described as I've said.
"overstating the MuCo guidelines isn't making your point, either"? I used direct quotes, so I don't see how you could get that. As to the rest of it, I don't see how you get a groove in water, which is what the earth is while touching the boat. It seems to me the best you would get are waves, but that wouldn't happen because once it stops touching the boat, it's just earth. But it's not my game. If you guys want to have Muto do all the stuff Rego does, go for it!
You used direct quotations entirely out of context and bent them to your own meaning, in addition, example spells based on the quotations of the effects also don't do anything close to the power you suggest. I was typing on my iPad and didn't feel like typing a lengthy response. Based on the existing spells, I don't see how you can get to a point that allows you to completely rearrange a human body. Now again, going back to your MuCo(Aq) spell, that would be perfectly fine and reasonable, and it still remains a high level effect.
This isn't a minor ability, nor is it even possible based on the effect. The effect you're doing is actually rearranging body parts. The minor ability is like seeing in the dark (example spell), or perhaps imparting keen senses or some other adjustment.
Again, this particular base effect isn't to rearrange body parts. The human form is fairly standard. Every body part has a correct position. Base 5 doesn't allow you to rearrange the body parts, doesn't even come close to saying that, it allows you to change what the person looks like. Human form is human form, it's not human form, when the legs are where arms should be. The example spell here is Disguise of the New Visage.
I think they would be two different effects. MuTe would make the earth like water but the ship would have to supply it's own power to move through it. ReTe spell would move the ship over the land.
I am thinking a Rego Herbam might be required as well to move the plants safely away while the ship passes.
I don't think my players will mind the ship tilling the earth, in fact, given their beardiness, its only a matter of time before they use it on the cities fields.
