You are completely wrong.
If you re used bushings then eliminating the flimsy stamped steel arm, or tightening the ends would have been the cause of eliminating the wobble.
You are welcome to adjust your uppers through out a range of castor settings and see for yourself. Since I've done this several times, on several vehicles over the years using settings from -3 to +10 trying to change the onset of death wobble I can say with utmost confidence that death wobble and castor are not related.
Neither Castor or toe have anything to do with death wobble, and if there is any change in the onset of death wobble via alignment settings that is an IMMEDIATE sign that the front end is severely compromised.
There are factory vehicles with castor settings that range from 0 to positive 8 degrees. They do not death wobble.
Not sure what you mean by toe pointing in the air. The lower the castor, the straighter your knuckles are.
What I do know is post like yours have casused a lot of people to waste money, become confused and ultimately frustrated, when they are trying to resolve this issue.
By the way, currently I am in the 400's for cases of death wobble corrected, and I have yet to do it with castor. In case you needed some perspective as to where Im coming from.