Thanks Renato this is very good contribute.
Of course, regarding step 6 ("Run each ETL at least once to import data") of course much better if you have a test env that inludes also test env of the orginal data source (e.g. a test OEM).
I would also add recreating Entity Filters and Time Filters.
Renato, very helpful indeed.
I just wanted to add another view to the topic. I agree with you BCO have isolation and simulation capabilities that make configuration and customization achievable directly in production, through staging. Still company policies may require (and they actually do in real cases) to build and test the solution in a Development BCO and only when validated let it move to Production BCO.
So, under this view, most of the items you mention still apply, but the other way around: from Development to Production.
Regarding  and  I recently worked together with BMC support on a detailed procedure on how to "elevate" a custom ETL from Development to Production, both for the first deploy and for subsequent changes (BMC knowledge base reference KA363173 on kb.bmc.com).