I thought about putting in inserts also. I will do some calculations to see if this a practical approach. In addition I will be closely inspecting the wheel at the points that I intend to drill for wall thickness etc. As near as I can tell there is no special reinforcing in the original location.
The suggestion of replacing the studs is an excellent one. They are really intended to be a static locator and I can tell that they have been hit dynamically quite a few times. The good news is that they are steel whereas the wheel is aluminum hence the aluminum is the material that gives.
The nut is tight and the clip is in place and has not slipped since my last tightening.
There is a lot of force being transmitted through this interface so a mere friction attachment is substandard.
I really wanted to do 2 things by this post: 1. get good advice (already being achieved) 2. To warn and inform the ST community. By the time I figured out why my rear end felt loose (no wise cracks

) I had already done the damage.
So whoever reads this: Put you bike on the center stand get some one to lock the rear brake and try to rotate the rear wheel. If it rotates at all even with great difficulty take off your rear wheel and inspect the hole/stud interface. Then we can talk. Hopefully this is an issue unique to me!!