Look, algorithmics isn't easy. It's not a bludge subject at all and requires a lot of dedication. If you're genuinely interested in the content and are up to date you should sail reasonably smoothly. Personally, having several years of java and python experience helped me because the subject involves a lot of pseudo code that needs to be analyzed, and a lot of the subconscious logic (for example, loop invariants) that comes easily to you if you have ever programmed before needs to be learnt if you haven't. I'm not saying you need programming experience, and VCAA certainly doesn't, but if you have even the basics under your belt a lot of the subject will have comforting moments where you say "Oh, I know that". Other than that, there's a lot you can actually learn before you begin the subject, such as all the different algorithms (check the study design) involved and such, which are splendidly documented on youtube. All this stuff helps you when the subject gets a little trickier, such as time complexity analysis.
I found it to be an interesting experience being in a subject that runs for the first year. Our teacher, who explained the content really well, was still learning the course and developing content for it while it was running, so a lot of times there were these moments where we genuinely discussed something before looking it up because none of us were sure of the real answer. It was unlike any other subject because of that, in a good way. Next year the resources will exist and the knowledge will be more established so I'm not sure if it'll be the same.
I can't comment on scaling, I think it'll be great, but we can only speculate. Do the subject because you want a strong foundation for C.S / I.T. in uni and the rest will (hopefully) follow.