Hi Gregory, Hi Keir,
Thanks for your responses.
I took the points -
For 1
As Keir mentioned ....
(my opinion) Best practice would be to keep Generics out of "real" assemblies. Exception is sheet metal (I'm considering making the flat pattern the generic anyway and the fully formed the instance). You would have a "real" assembly and corresponding Part Structure for each assembly instance (and/or assembly using instances).
For 2
This seems to be a customization
For 3
As Gregory said there is an option OOTB which I have tried already - Unfortunately failed as it is a bug in 10.1 M030
Any other options ....