Hi there,
Interesting question! However unfortunately the answer is no, Bulk Edit does not support updating tasks *inside* of projects, and so you could not use it to update insert / edit tasks as you suggest.
Something like Nintex workflow may allow you to do what you need using workflow if this is a frequently required change, or failing that perhaps a VBA macro in MS Project could do what you need with minimal development?
Hope that helps,
Martin.