Having neither the will power or time or energy to check your calculations I'll accept them, there are numerous factors to consider though, its not as simple as whether your anchor points and harness can take the load applied but also
*what direction the load is being applied (this isn't straight forward as in an accident the load can be applied in cyclic motion or in 2/3 planes at varying angles
*what shear factors are introduced at each load point, can the material handle it?
*Where is the absorbed kinetic energy of impact being absorbed into?
There are even more factors involved but these are the main problem areas.
The simplest way to engineer a solution is to double up on values - ISO standards for structural designs is max 49% - that is the anticipated load of lets say a bridge should be a maximum of its calculated capacity.