Reusing RDLC document layouts in NAV2015

Let's say you invested days into designing the RDLC layout of the sales invoice, exactly replicated the format that was used in the previous software.

1) What is YOUR best idea about how to make everything else from credit note to sales order or quote like almost the same? Especially asking people who work at NAV solution centers, as multiple developers brainstorming may come up with better ideas than someone working alone like me not talking to other experts.

2) My idea is exporting and importing Custom Layouts. As long as the dataset is edited to be the same it should work? Can someone confirm it?

3) If my idea is correct, here is something weird. I can edit the built-in layout in the Dev Environment. I can copy it into a custom one, export it and it is the correct one. But I cannot import it back as a built-in layout. Even if I import it as a custom one for other report, and set it to use the custom one as default, if I edit it from the Dev Environment it is not that layout but the original one. Thus I could only edit the imported one from the Custom Report Layouts / Edit Layout, but since I cannot install (for reasons) the NAV RTC Client and the Visual Studio on the same computer, how can I do it? No not in SQL Report Builder that does not work well.

Just any general ideas how to replicate the layout between documents fast?