MY UNDERSTANDING:
So how the UNSW guaranteed entry system works is you will always get an offer if it is your highest ELIGIBLE preference. So let's say you received like a 94 ATAR (including hypothetical bonus points in this hypothetical situation lmao) and you're applying for BEco at UNSW(guaranteed entry) but also want to try your luck at BComm at USYD due to the chance of a change in lower ATAR this year. As such you put first pref as BComm @ USYD and second BEco @ UNSW and whatever etc etc. Three outcomes can occur:
1) BComm at USYD is lowered to 94. In this case you would get an offer into BComm at USYD but not your guaranteed entry into BEco because you can only receive 1 offer every round. Congratulations on BComm @ USYD!
2)BComm remains above 94. In this case you should be fine to get into BEco as it is your highest ELIGIBLE preference(obviously because your ATAR didnt make the cutoff for BComm @ USYD) in which case you're golden and you would receive an offer due to your guaranteed entry! bloody legend!
As for your second question, i think what you mean is scenario three where you are offered a place at BComm @ USYD but still want to go to BEco @ UNSW. In this case, you fucked it mate, because BEco is extremely competitive and usually dont have vacancies after main round. In which case congratulation again on admissions into BComm @ USYD!(To repeat, you are not given more than 1 offer, if you make it to BComm @ USYD you wont get an offer into BEco @ UNSW even if you have guaranteed entry) In which case admissions into BEco @ UNSW becomes impossible due to lack of vacancy after main round.
Ultimately this was obviously a hypothetical situation and would depend on your exact course choices. This is just my understanding of how the system works through contacting UNSW enquiry hotline, emailing etc etc if someone knows something that i fucked up then correct me lmao.
