I don't want this to come off wrong, but you can... stop giving me advice now.
I shared my original post not so much to request advice as to just share what I was playing and how things were going. I can't seem to convince you that while I'm not an expert, I know what I'm doing, and so basic stuff like that is not going to be news to me.
(Btw, I also play on Hard, which buffs other countries in a few ways and adds a -20 relationship penalty agaist every diplo action automatically)
I never said Austria would join EVERY war. They do, however, get called into a lot of them that you declare in the area, which you'd 100% find out if you continue to play. I was talking not just about Austria, but about other huge allies. For example, the remnants of Bohemia in my game is currently allied to Sweden, Lithuania, France AND Italy, which off the top of my head is somehow around 400k troops.