I FINALLY GOT MY OWN WAY OF DOING IT! AND SETTING A SHORTCUT ON PREMIERE CS5!
You can set the shortcut for this one.
Go to EDIT menu, then select KEYBOARD CUSTOMIZATION
Then notice that you have a dropdown list that says [Application]
And select [Panels]
From there, open-tree the [Project Panel] and select [Open in source monitor] and set a shortcut.
I set the enter key, so now when i hit enter, it opens it for trimmer actions, and doesn’t rename it, for that, I use ctrl+enter