there should be a libary of models pre-approved for commerical/marketing use
Most people that want to use Grabcad models for commercial use don't want to resell the models. They want to use the model to demo something else, some other software...
Posters should be able to "approve for commercial use" upon uploading, and that should go in a special library
In this era of design automation there is no need to keep and maintain a library of pre-approved designs. With design automation the marketing and sales team can get the 3D model, GA drawing and Cost sheet by giving technical input as per the customer's requirement. Yes, there are some limitations to the design automation and I guess those things will be eliminated in coming couple of years.