Touchcad is your best option, at least it can do some of rhino stuff and can do some of prosurf stuff, best choice, the only problem I see with touchcad is the lack of formats to export to, for example, it has no iges, or step export and import (maybe it has that feature by now) which are some of the most used way to export a nurb surface to other systems like think3 or solidworks etc..
a surface that is not a nurb surface, usually is a mesh, it can be something else but most of the time you only work either with nurb surfaces or meshes, meshes are not so easy to edit, nurbs are becoming a good way to represent surfaces like the ones for a hull and more "editable" in other software's.
"if you have your hull created in prosurf,you export it in think3,and then you create a "loft" surf between starb&port sheeline,what kind is this surface of?"
well.. the actual surface is the deck...and is a nurb surface.....lofting, is just a way to create a surface.
now...what I like to do in solidworks is to create my models in rhino and export the surfaces to solidworks, and create the structure "in" the surface, that way if I want to change anything on my surface all my structure changes with it. but...so I'm guessing that you want to use think3 (based on your example) then...you probably export only the sections of your boat as a dxf and use this ones as a reference in think3 to model the boat structure.