Not too sure about the specifics of the degrees but the typical economics majors (economics or econometrics) are math based and stats based respectively. First year, not so much, but later years have a lot of applied maths/stats (which you'll learn in first year uni). Financial economics is more like "wolf of wall street" sorta stuff. USyd would probably have the same quantitative focus as UNSW so don't worry too much about that. I guess the quantitative applications make economics a discipline which is 'evidence' based as they use empirical methods to test and confirm theories.
Have you considered a Bachelor of Arts? This way you could major/minor in economics and perhaps politics or social policy? There is also a BPPE
https://www.handbook.unsw.edu.au/undergraduate/programs/2019/3478 at UNSW which looks more "thinking" based rather than applied maths based.
Regarding BCom, it's more business based so you'll be doing bits and pieces from marketing, management, accounting, finance, until you settle on a major, which might not be what you want to focus on (given that you're interested in economic thought).
Just a side note, but one of the teachers at my school "fell in love with HSC economics", then enrolled in BEc at USyd, then changed to Arts as the quantitative focus wasn't her thing.
Sorry if this isn't much help but hopefully you can make a choice
