quite true for sure. I teach welding for a living, so keeping up with AWS and ASME standards is a part of my day to day life. If your not at least somewhat immersed in it, it would be hard to.
All that aside, for garage use, in the USA, those would be the "have in the shop" standard for me imho... but you are quite right, none of that does much to help ryan over in Germany, and for that I apologize.
Also Ryan, one thing I can say is Yes, Pure argon will do you just fine. Bottle size matters not, just changes how often it will need refilled obviously.
Also, I am a teacher, so I am biased, but if you are able, I really feel that a short term welding class would really set you on the right path. Get started with good habits and techniques vs. bad ones.
For example, where I teach, I have a 5 night, 20 hour "intro to welding" course that costs about $189.
We don't tig weld in that particular class(mig, stick and oxy acetylene safety and cutting), but it would still help you get a few fundamentals.