Yeah it is currently used only for uploading/downloading machine profiles. There used to be functionality to upload/download tools and cutting data. But I removed it because nobody used it. I will later replace it with a full database backup and sync.

No, you need to rotate the sketch plane 90 degrees.

That error message is basically telling us that you've got a Machine Definition which doesn't match your WCS/Tplane/Cplane setup. So the Z-Axis of the WCS/Tplane is not aligned to the Z-Axis orientation of the Machine Definition. Or, there is a bug in Mastercam. The former is more likely than the latter, but bugs do occur. You should create a Zip to Go file, and attach it to this thread...

Gotcha. I do this often when I'm using something like the Big Kaiser Mega Micro collet extensions. I usually just make it part of the tool holder.

What do you have selected for your Axis Combination? Save your file, and close it. Use the Machine Definition Manager to open the Machine Definition. Open the Axis Combinations Dialog Box. Right-Click in the Axis Combinations area (white area), and choose "New Axis Combination". In the "kinematic tree", choose the X, Y, and Z Axes, and check the "spindle", and "machine table". This gives you a "work holding component", and a "tool holding component". Name the 2nd Axis Combination as "3-Axis". Save the Machine Definition. Open your Mastercam File, and do a "replace" on the Machine Definition. Open your Operation, go to the Axis Combinations, and select "3-Axis". Check your Planes, and make sure that WCS, Tplane, and Cplane are all set equal.

As it turns out, it appears to just be for the machine profiles and nothing else. At least not that I can see.

I'd be curious to know as well. However, I am always curious about anything 'cloud'. Where is it really stored, and who might have access...

It is tied to a Post it reading the mi and mr vales to help, but I am not aware of NC code Verification at this point. They have no control emulator built so until that happens they will never be able to emulate what other true CAV software are doing that have control emulators that take machine parameters and use them to simulate not only kinematics, but macros, variables and other things Machinesim is not currently able to handle or support. Again this is my understanding of where thing are and I can be wrong.

Verify no way I am aware of. Machine Simulator maybe, but would need a custom post built for the machine simulator. The best solution would be an external CAV (Computer Aided Verification) program.