Can I use a Dashboard created in one space in another space?
I don't believe so but you can copy the dashboards and reports using a copyspace command (though you would have to maintain them in multiple locations)
No collections/dashboards cannot be referenced through Network BI in another space. A best practice architecture is to have a space containing the model and another space containing the visualizations which references the Model through Network. This method lessens the maintenance by not redundantly maintaining the model, allowing easy copying of the visualization space.
