That's actually not true. Somewhere from 1923 to 1937 Germans had one or two ministries in every Czechoslovak govermment. German members of Czechoslovak parliament had maybe more power to influence Czechoslovak internal policy then Slovaks. Your oppressed Germans had bigger share in officer corps then Slovaks. German schools, high schools and universities were allowed same way as Slovak and Ermans had up to 1938 if memory serve me right at least one more university then Slovaks. Sure Czechs were somehow preffered over Germans or Slovaks in some positions but still Germans had probably more rights then any other minority at that time in Europe ore anywhere else.
I was referring to language rights in government, which AFAIK weren't granted until the late 1920s. My reference was to what was going on in 1918-19 for politics going forward; it becomes more important to reclaim Sudentenland with Austria in Germany, than Danzig and the Polish Corridor.
Back to the topic. German Austrian unification after VT would probably lead to little big bigger investments in the Army and probably much earlier fortification of the borders with Germany not leaving Austrian border only ligjtly fortified.
Certainly, even with a reduced German/Austrian military (probably limited at 125,000 ITTL).
This situation would also very likely lead to Czechoslovak Polish agreement with Czechoslovakia maybe ceding Tesin area to Poland to get Warsaw on its side.
This is highly doubt. The Czechs aren't going to give up a Czech majority area, as the Polish part was already given to Poland in 1920 AFAIK.
https://en.wikipedia.org/wiki/Duchy_of_Teschen#Aftermath
It was too economically important to let go, especially as they were already allied under the Little Entente, which France guaranteed. Poland only got 'off side' in 1933-34 when Hitler and Pilsudski signed the non-aggression pact.