Your mind is made up so I know this is a waste of time. Your wild ass statement about a diamond blade kicking back and cutting a man's neck is pure hyperbola, fiction, and prevarication. A diamond blade would be very hard pressed to cut your hand if you ran it into your hand at full speed. They do an excellent job cutting really hard things like glass and tile, they really suck on anything else.
I have no idea what an alligator saw is. I've been in the commercial contracting business for over 50 years so please enlighten me as I may need one some day.
You may not be strong enough to hang onto a grinder when the blade hits something, be it a tree root or whatever, but I sure as hell am and have done so, though that is NOT the object when using the tool.
The reason most us have said to not use the grinder with a blade has much more to do with the OP's opening line which said that he was not experienced. Let it alone.
I really hate it when people babble and pontificate about things of which they have no experience. If you have information or experience to share, have at: otherwise, sit back and listen (read).