Dear Stéphane,
Thank you for your query and for moving it out from our private LinkedIn discussion here into the public space.
Here are some suggestions on various topics:
Getting started with the Revit API:
https://thebuildingcoder.typepad.com/blog/about-the-author.html#2
Before getting started with the Revit API, you should acquire as much knowledge as possible about Revit from the end user point of view.
I would assume that you already have that 🙂
Here is one very old analysis of integrating Revit with an external database:
https://thebuildingcoder.typepad.com/blog/2009/01/database-integration.html
Many things have improved significantly since then, and your target is probably quite different (and much simpler than) the one discussed there.
It might still give a few hints.
Good luck getting started and looking forward to continuing this discussion once you have started exploring in more depth.
Oh yes, by the way, talking about dashboards and things:
I would strongly encourage you to look at a partially cloud-based solution, to provide convenient access to a much larger audience in a much more scalable manner, with access to a huge number of public domain JavaScript-based libraries that can vastly simplify your work and integration efforts.
Here are some of my own samples integrating desktop and cloud:
https://github.com/jeremytammik/FireRatingCloud
They are also already pretty dated.
Since then, Autodesk has made significant progress with Forge, and Forge design Automation for Revit is just around the corner:
https://thebuildingcoder.typepad.com/blog/2018/11/forge-design-automation-for-revit-at-au-and-in-pub...
Maybe the will provide the most efficient path forward for your project as well?
I hope this helps.
Best regards,
Jeremy