Aussie Junior, I’ve skimmed most of your other threads, and have somewhat an idea of what you are looking for. You’ve gotten a lot of advice from folks. There is another Australian student, @akova1, who asked some similar questions. Here are a few observations in a nutshell:
Applying - The common app in the US opens August 1. Very generally speaking, the sooner you apply, the better the chance of receiving merit scholarship money. You probably understand the difference between merit and need-based aid. You are looking for merit aid. So, if I were you, I’d have my research done and choices ready to go by August 1, since the mechanics of applying (essays, recommendations, getting all your docs together, etc.) will be taking up your time from then onward.
Timing of decisions - Some state (US public) universities have rolling admissions and some Liberal Arts Colleges (LACs) have Early Action admissions that let you know quite early. My D had acceptances (together with aid awards) from Wells College in New York and The College of Wooster in Ohio by the third week of November this cycle. There are others that she will not hear from until March. It runs the gamut. Just be prepared for that.
Testing - You’ll need an ACT or SAT score (caveat: There are numerous “test optional” schools, but there may be added hoops to jump through, and it may adversely impact your aid chances by not taking the test). Take the test ASAP. Try to take both, because students often do significantly better on one than the other.
Aid awards - A “full ride” will be difficult to achieve. It is much more likely that you might receive some offers of “full tuition” (room & board cost would be another $12K or so from your pocket), or partial tuition. So you need to have a frank discussion with your parents about what they can pay, what they can borrow, and the “window” of awards that you would be able to accept.
Applying strategically - there are many approaches to this. You might start with universities that have traditionally or historically had a special relationship with Australia, such as UT Austin, Penn State, Arcadia University, Georgetown (CANZ), or Rollins, for some examples. Maybe apply to a few of them, because your “Australianess” might be a hook. Then, there is a sweet spot of LACs, such as numbers 40 or so through 100 in the USNWR rankings, that are not as difficult to get into as the top tier, but where you can get an equally amazing (or nearly equal) education. Some of these offer substantial merit aid (College of Wooster, Hendrix, Centre etc.) and some have special circumstances. For example, Earlham College is hoping to grow the size of its student body by 50 or so students a year over the next several years. We met an Eastern European student who was there on scholarship, and was very happy with her education there. Look at the Common Data set for each school, and the number of international students they have. Some with low percentages of int’l students might be looking to grow their numbers.
You are interested in writing. Definitely look at Sewanee and Kenyon which have very strong writing programs. Also the College of Wooster which has a strong senior thesis program (students have written novels, plays for this).
So, in summary, divide your prospective schools into about three categories, and then apply to 6 or 7 in each category in order to cover your bases (an American expression there, sorry). And again, do it early. Don’t worry so much about grades; they are looking at the whole package. US students don’t have their final year grades either, when they apply.
Good luck! And good on ya for looking to expand your horizons!