Hello mstrengell,
Regarding the crash, try Software rendering mode (Tools, Options, Rendering). Also, turn off the edited IntelliShape during edit (right-click the background during edit, select Show, "Hide edited IntelliShape). Let me know if that resolves the crashing. If not, try updating your graphics card driver.
This function could definitely be improved. The problems creating fillets seems to be the function is very picky about where you drag the cursor after clicking the vertex. See the attached video, the fillets are all possible but the cursor drag location is critical. I'm going to file an Enhancement Request to ask for this to be less demanding of the cursor drag location.
3D_Curve_Fillet_Creation.zip