Note that Markus his email is 6 years old, some things have changed since then :)
On a conceptual level, query printers take a query result from an ask query, and create some visualization for that. At least by approximation, the internal code does some odd things at the moment and some printers do further things. This is however where we want to move, and what we will need to do if we want to share result visualization with the Wikibase project.
If what you want to visualize is not the query result of an ask query, then using the result printer infrastructure is not the way to go. I suggest you instead create a parser function that has an interface suited for the task at hand. Once it is clear what the inputs of this function are and what you want to get out of it, we can determine what the most efficient way to talk to the SMW store is.
At least for me the easiest way to give the feedback/advise you are looking for is if the code is written up to that point, so there is an unambiguous specification of the inputs. Can you post this for review somewhere?