I played Venice on FtG recently, should be same thing:
-Focus hard on Macedonia and Thrace, you need them to stop the Turks. Absolutely necessary.
-Hungary is kind of waste of time to be honest just grab Dalmatia and go.
-If Austria is allied with some HRE minors and one of them is alliance leader you can cheese AI by offering 200-300 duckies to them. OPM Hesse or Saxony will accept happily and screw Austria over.
-Overall sometimes once you get DoWed literally try offering white peace right away and they might accept - or just pay them off - this works too.
-If you absolutely have to fight: not sure if that's a thing in EU2 AGCEEP but Venice (province) can be blocked by the navy. Trap large Austrian force in there, let attrition whittle them down and then finish off. If you have Mantua/Lombardia lure them there and wipe wipe wipe with CAV (early game)
All I can say off the top of me head