1.30 seems to be a very good patch, but this really mars my enjoyment of it. However, the Pope always joining the HRE is very close to a game-breaking bug that needs fixing asap.
Generally, AI countries join the HRE much too easily in 1.30, which breaks both the immersion and game balance (because the IA gain makes it much, much, too easy to pass all the reforms), and this is something that ought to be reconsidered in a patch. The Pope always joining the HRE should be dealt with urgently in a hotfix.