It all depends on what you are trying to achieve. Elmer may serve your purposes with regards to analysis of fluid mechanical problems, but can be tedious to create models in, compared with TurboCAD. TC would be fine for modelling for any purposes other than analysis of this type. In my experience, I would not try importing anything but very simple models into any FEA/FEM software from a CAD programme - there are too many pitfalls for the unwary. To get any meaningful results with FEA/FEM your models must be very 'clean' and fault free, and, you must be able to prove, by other means, that your results make some sort of sense.
It's a case of 'horse for courses'. So, compatibility is going to be very limited.
Use Elmer, or LISA perhaps, for affordable/free problem solving, and TurboCAD for 2D/3D models - for presentation/manufacture, whatever.