sibt north ryde is much larger and the grounds are nicer. you will have access to all the main macquarie campus facilities like the library etc. the lecturers are good at both. both are really multi-cultural. I dont think you have to worry about the train trip being dangerous.
If you do a diploma of arts at SIBT, you can get straight into arts edu and have the diploma count for your first year so basically you're already into macquarie when you go there. should be much easier than transferring.
Re: Alternative pathways to your desired university degree
you could do a bridging course. my sister just did her hsc but couldn't complete enough subjects for the atar and she wants to be a teacher. she's going to do a dip of arts at SIBT then go into BA of arts-education at macquarie. maybe...
if you want to get into media and you don't get a high enough atar you can always do a bridging course. i did a communications diploma at sibt and got straight into media at macquarie
i had a look at both insearch and sibt and i decided on sibt. macquarie uni campus is really big and has lots of trees and space. when i went to the uts open day the grounds were smaller and there wasn't as much interesting stuff happening. if you want to study commerce at mcq definitely pick...