Exactly but his name does not reference his transportation but rather the overt phenomena around what he does while transporting.
Oh I agree completely but their name just references that they spend time in the sky not that they can manipulate gravity.
I agree to a point but cohesion is so inherently suited to building that it seems odd you would opt to use soulcasters instead. True you have to import mass but in the mind of an organized builder that is an advantage as you can also dispose of rubble efficiently.
I personally do not think that either the surge of Transformation or Cohesion would be particularly suited to making a bio-weapon. Given that her other interests are in bonds, spren, radiants, surges, and oaths I would actually peg her as something more analogous to a Truthwatcher if we did not have context. I think it more probable that she created the bio-weapon through conventional means.
I don't think soulcasting an organic material that does not yet exist would be particularly easy for a soulcaster. We have seen they can copy existing ones pretty well but making something from scratch seems a lot harder.