I think you are misunderstanding the purpose of rosetta...
There are three types of apps that you can use on your MacPro through OS X
1. Intel, which can only run on Mac Intel systems. These are not Windows apps, BTW. Rosetta can't be forced with Intel apps
2. Universal, coded for both Intel and PPC, and run natively - no rosetta. You can choose to open these with rosetta if you need to use older plugins, and some types of hardware drivers that are not yet universal.
2. PPC, which will not open on an Intel Mac without Rosetta. You can't force PPC apps to open WITHOUT Rosetta on an Intel system.
Why do you need to force rosetta?
The rosettaTest seems to only affect the icon on running apps, and does not display anything, if the app is running natively.
So, there are 2 modes for an app to run on your MacPro: Native, and Rosetta