With regards to the indicators, you can put them on the connector pane to be returned from one VI. In your next VI, the one you are trying to pass the values to, you need to create controls that are the same type as the indicator. So, if one VI has a string indicator on the connector pane, your next VI needs to have a string control on the connector pane. You can switch a front panel object between control and indicator by right clicking it.
Have you gone through the 3 and 6 hour tutorials here? I suggest doing this because it will save you time in the long run.
To call the VI, you have the right idea (I think). You can either launch your second VI dynamically (search the forums on how to do this), or you can use a property node to set your front panel visible property to false. This will hide the current panel. Then, in your subVI (the one who's panel you want to show) you can go to File->vi properties then under windows appearance select show front panel when called, and close front panel if originally closed. I think that will give you what you want. But, again, I suggested the tutorials.
