[ros-users] Stage Vs. Rviz

Hello all,
Repeating same question as i haven't got satisfactory answer from my own
study.
I would like to know some basic difference between stage and rviz through
following questions:-
1. If we my navigation stack is set so as to visualize and simulate then
Can we replace stage by rviz ?
2. Can we have amcl, map, costmap2d - Global and Local and planner
algorithms in place and see robot reactions in rviz?
3. Can we totally eliminate stage from use?
any help??
thanks,
- Prasad