It does not take long to learn how to design the parts in Fusion. If you are only wanting to CAM the parts, you would still need to know how to add sketches or other features to an imported file whether the file be a Fusion file, a stl file or a step file… I don’t see how someone can use CAM without knowing the basics of 3D Solid modeling design. The videos and tutorials will walk you thru it pretty quick. IMHO
Fusion allows you to easily switch between metric and decimal inch. It should not matter what format you wish to design, but if you want to CAM in metric, switch it to metric when you CAM and post.
http://titansforum.titansofcnc.com/t/no-option-to-download-models/5765/14?u=stephenhadwin