In complex model scenarios could calculation take more time. Usually, it is caused by many objects. The solution could be to merge parts and reduce the number of objects. Also is recommended to divide the model into smaller parts and run commands separately. 

Some 3D software works on different principles than 3D modeling with mesh. Most BIM software works on parametric principles, where 3D elements carry a greater amount of information. These are, for example, Revit, Allplan, and Archicad. Other software prefers to work with mathematically defined Nurbs smooth surfaces, which are then suitable for production. For example, Rhinoceros is a representative. Some programs have their way of hierarchy and creating 3D matter, and this category includes, for example, SketchUp. When converting to Mesh for universal processing, it is advisable to use basic cleaning processes.

We recommend using FBX in general.

Sometimes you don't have plugins that can do it from your software. In the second place is the preferred OBJ. For SketchUp is the best alternative DAE format. 

Yes, if users would be interested, new cleaning functions could be added. Let us know. 

Everything will be included in a single purchase of software.