It's always smart to mark the plugs with a wax pencil, marker, something before taking them off, then you don't have to manually check torque. Maybe with a new crush washer if your worried but it's pretty spot on in the past when I do it and verify with a torque wrench
The leak in-between the engine and transmission can be a few things. And depending on what it is. It may be warranty by Audi bc of the diesel gate skandle. Unfortunately the only way to find out is to take it to an Audi dealership and have them diagnose it.
I have everything I need to change the trans oil / filter but right now I'm very limited on time. Hopefully with in 2 -3 months I'll make that video. Once I'm not busy with other stuff. I promise I'll make that video