usually i use the naca 65a009 and it has a sharp trailing edge made of a circular arc when i need to make a root fillet. the le is an ellipse. the model attached here is for a computer case fan. the airfoils are all stalled so it is made of a flat plate. usually you would use a circular arc for the le and te. however, i wanted to experiment with ellipses for the le and te. i wonder if your solid is valid. the line in your second picture, in the fillet. that is where rhino fails almost all of the time, until i shrunk the fillet way down to .08mm. it does create fillets at bigger values, however, they are all invalid. that's the problem i have with rhino. it either fails to make a fillet or creates a garbage fillet. if you battle with it forever you can usually get a good fillet out of it. but it's not at all easy. i'm not sure how to test if your model is valid. i saw you can calculate volume with the v4 beta. the other way may be to export a step file. i can see if it will mesh with netgen. in rhino for the larger value fillets if you zoom in where that line is you can see the fillet is actually mangled. but as the radius shrinks it becomes impossible to actually see what's going on.