I did Further and Methods in year 12.
I loved Further and absolutely despised Methods. In my opinion, Methods gets a lot harder at the end (well at least for me).
I'd probably talk to your school coordinator or counsellor about the courses you're interested in. It also really depends on which university you want to go - pretty much the Melbourne GO8 unis needs methods study score of 25.
I don't really think Methods is a good backup plan other than if you're planning to do engineering or a specific maths major at university, though I only thought about this superficially so don't quote me on this.
Further Maths isn't hard to understand, it's just hard to not mess up. However, once you smash out VCAA papers you would find out that most of the questions, if not, all of them, are pretty much the same, just worded differently.
For methods I've been averaging like, 50-60s the entire year- the only reason why I'm hesitant is because I haven't necessarily actually sat down and tried to study for any of the tests either- so I'm just wondering what would happen if I actually tried ahah
Oh boy I feel you on this one. I averaged around 30-40% for my tests in year 12 (I'm pretty sure the highest score I got was like high 50's). I don't have too much advice for study on this as I myself didn't do too much for methods, but of course if you actually tried you would do great.
If you really feel Methods isn't your forte, then I'd really think of switching. However, it definitely alleviates the pain if you understand the concepts. Appoint another meeting with your methods teacher, they'll be sure to help you out further.