It isn't actually at restrictive or bad, you'll find you can get into almost any of the 2nd year units if you structure your first year right. Just look at the possible majors you have in mind and what subjects they need. BIO will open a lot of health sciencey doors and math's will help for engineering and things like that.
Even if you change your mind in 2nd year you always could take a 1st year unit if you really wanted to but that'd be a bit screwy degree wise.
I See you're also considering monash, let me get a couple words in here:
Monash is a lot more restrictive than melbourne (i think so), read the "
Breadth of Studies" section and you'll see what i mean.
I think personally
Option 2 is the better way to go because for
option 1 you need 3 sets of 2 sequences so thats 6 things you have to take where as
option 2 you only need to take 3 subjects. The downside of option two is you may like me, not like one of the groupings, i myself didn't really want to do any of the earth science subjects.
It's one of my reasons for considering a transfer to be honest, i don't know why they impose a structure so restrictive.
I have a couple gripes with it though that might bias me: I gotta take an earth science unit i dont want, My math unit isnt recognised as one of the math units that would furfill the math requirement listed there... so i have to also do a stats unit or something which i also don't want to, it doesn't sound like a lot but thats essentially 2 units out of 8 blown on things i dont want to do, 25%. I didn't get any room to do some electives (that was one of my major reasons for looking forward to uni, doing some electives subjects i had in mind), this also majorly pissed me off. This only applies to plain BSc though not advanced.