cafeconleche
Registered Users (C)
Austria is quite difficult about dual citizenship. They're stuck in the 1800s with regard to nationality law (like Germany and the Netherlands, which are are slightly more liberal but not by much). The OP has to prove strong ties to both Austria and Germany to show a need to have both nationalities. The bureaucrats in Austria will try very hard to refuse it, so it's not a sure thing.
So, the Re-entry permit route (or Permit to re-enter) is best for the moment given the time crunch. Apply for it now (if you can afford it), even if you might be able to apply for citizenship soon. Having it does not jeopardise your eligibility for naturalisation; only being outside the country for long periods does. They tend to allow you an RP for about 5 years of time spent outside the US, so if you apply for it now and end up using it only a year after you get it, then you might even get 6 years worth of RP. The only issue would be whether you'd request they send it to your US address or a US mission in Austria. You could, to be on the safe side, request it be sent to a third-party in the US who does not intend to move in the near future, so there's a fixed address to get it. Remember that it might also take many months to process, so you might even be able to stay out of the US for longer than the RP validity dates.
So, the Re-entry permit route (or Permit to re-enter) is best for the moment given the time crunch. Apply for it now (if you can afford it), even if you might be able to apply for citizenship soon. Having it does not jeopardise your eligibility for naturalisation; only being outside the country for long periods does. They tend to allow you an RP for about 5 years of time spent outside the US, so if you apply for it now and end up using it only a year after you get it, then you might even get 6 years worth of RP. The only issue would be whether you'd request they send it to your US address or a US mission in Austria. You could, to be on the safe side, request it be sent to a third-party in the US who does not intend to move in the near future, so there's a fixed address to get it. Remember that it might also take many months to process, so you might even be able to stay out of the US for longer than the RP validity dates.