For looking at different seastead designs we would like to have a "parametric CAD model" that can then be used to generate:
1) files for 3D printer to test Froude Scale Model in water/waves
2) files for capytaine.org simulations to get idea how it works in waves (or some other way to visualize different wave sizes and periods)
3) files for finite element analysis (FEA) software to test structure strength 

We might or might not also want to do the following:
4) files for 3D printer to do "scaled structural modeling" using plastic to get some rough idea if aluminum full scale would be strong enough
      If our plastic model is scaled down by 50 from the full size can plastic give us some idea what aluminum would do?
      What rules can make this helpful?
5) files for computational fluid dynamics (CFD) to test how it works in waves using computer 

We have been using AI to generate 3D models in openscad saved as .scad.   This can also output .stl files
that we then slice and make gcode files that our 3D printer can use.  So we have been doing #1 above this way.

Is it reasonable to use a single ground truth 3D drawing in openscad that all other files we use are derived from?   
How would you structure it?
For east of 3D printing we have been breaking the .scad file into several different files.
Is there good way to specify how these different files fit together to make the full seastead?

I strongly prefer open source software.  I also have been very happy with the help AI has been 
in making the openscad files.

Is there are CFD or FEA software that works well with what openscad can generate? 

Is there some better set of software that so all 4 of these things can be done off one base model?

This is at the brainstorming and searching for possible designs stage.  We want to have something that
we think has a good chance of working well before we start paying the naval architect. 
We will have a naval architect do the final engineering before any full scale stuff is built. 
So we don't need the NA level of detail yet.  

Are there other set of tools you would recommend for what we are trying to do?