1. If US dollar becomes weak, then of course both EUR/USD and AUD/USD will rise. So net effect on EUR/AUD will be minimal. Besides AUD is little more advantage in terms of interest rate advantage. ECB is talking about more stimulus while RBA is on hold.
2. If USD roars back knocking everything down, then also we believe AUD/USD is more supported than Euro .
3. In terms of nearby resistance levels, It might be tough for Euro to break 1.1500 while for Australian Dollar 0.8000 is still 300 pips away.