SAP Solution Manager

Dear Friends,

Please suggest me in this

We are planning to implement Solution Manger in our organization.

1. SAP recommends to install 3 isntances of SAP solution manager (DEV/QA/PRD), but is this really necessary if you are only going to use SSM for monitoring, analyzing and service platform?

2. In which case is it beneficial to setup a 3-system landscape?

3. Are the standalone engines CA Wily Introscope and SAP Loadrunner by HP necessary components?

Thanks,

VKP.