Whipsnade put away your barbs and look at the idea for it's worth in play and approach it with that in mind, not trying to win points in an argument here...
Dial back your sense of umbrage and re-read my original post.
I brought up a long discussed problem with planetoid hulls and posted a link to another one-person trader design. I made no judgment about your design specifically.
I just think such a processed hull would be easilly mass produced using the low value metals they were not going to sell as refined metals.
I think you're wrong, especially with regards to the "easily mass produced" and "low value metals" claims. Seeing as you've totally ignored cooling issues such structures would face - we're still cooling the Hoover Dam several decades after it's cement was poured- there are many problems with your suggestion.
The idea would require a house rule regardless of which rule set you're using.
Then present it as a house rule.
I happen to agree that ICE roids would be a very tough engineering challenge...
There are no "ice"-roids of the kind people usually assume just as most planetoids are not the tough unitary structures of the kind people usually assume.
... though I do seem to recall a rather large one used in the "sky raiders" adventure series.
That recollection is faulty.
... the dew line...
The mind boggles.