Yes, I do understand not wanting to break anything in production while upgrading. What you can do is email customerservice@wowza.com and request a testing license. That way you can upgrade in a testing environment first and make sure all is ok. I always encourage people to open a support ticket when upgrading and have an engineer check the files and and run tests to make sure nothing will break when you switch from testing to production on the new Engine version.
As far as Nvidia cards, we have a lot of updated articles in our docs so check it out:
Lastly, feel free to ask and tag one of our community experts in the Streaming Engine forum like @Karel_Boek who can answer some of the more deep technical questions you’ve mentioned. He has a wealth of knowledge in all areas related to Engine. Hope it all works out well for you!