You don't sound arrogant at all, don't worry about it. You realize some things over time, and your standard for playing musically may change as well as you develop. I think posting a recording would provide the clearest indication of your actual level. If you have an mp3, you can actually upload files right here in your post as long as they are under 50 MB in size. I don't doubt that you have played the pieces you mention, but the level of musicality (it's not a binary thing) is very important to make an assessment.
The thing is basically playing the octaves clean at a decent speed and not getting tired.
Playing the octaves is much more about efficiency than it is about endurance. You will need to practice certain movements with your wrist, and playing in groups with micro-relaxations.
And something to mention is that I'm 12 years old right now, and I will play the piece when I'm 13. Which means that I have 1 year of practice time for playing Liszt and one or two other pieces (probably not as difficult).
1 year is actually not that long a time when it comes to the development of piano skills. It is about what I would expect for a piece which you will be using for a competition.
My relatively slow progress is mainly because of my 1st teacher, where I have basically gotten nowhere (in 3 years Rondo Alla Turca, played like absolute sh*t). If I had my current teacher since the beginning, I would have gotten way further with my progress. I had my current teacher for 2 years and went from the Rondo Alla Turca, to Hungarian rhapsody.
Your progress is not relatively slow, it is very fast by normal standards. Especially if we're talking about playing it well. Playing Hungarian Rhapsody 6 after 6 years is not typical at all. Which is why you need to be careful that you are developing all of your fundamentals adequately.
Btw, the piece my teacher suggested first was the Khachaturian Toccata (which I will learn after the competition now). After my lesson she said: "It is pretty nice to play such difficult pieces." And she didn't mean, to just play the notes, but play the piece musically.
I have had teachers tell me this exact thing. Now, I don't want you to get the wrong idea -- I don't know enough about you or your teacher to comment. But, there is a difference between struggling with a piece and playing it with command. And from your experience, it is unlikely, statistically speaking, that you are able to play it well with command. I've had the experience where I worked on difficult pieces with a teacher, and they were played pretty musically as well. But when I showed it to some pianists, I realized that a lot of things were lacking in terms of quality of the tone, touch, phrasing, technique... Just something to be mindful of. The HR6, if played well, is a difficult piece even for conservatory students. Sometimes, we learn a single difficult piece. And just so you know where I'm coming from, I also learned Chopin etudes op 10 no 12 and op 25 no 12 some time back, but they weren't truly at the level they should be, and my time would not be well spent by working on those extensively for 6 months, for example.
Also, you said that you went from playing the Rondo Alla Turca poorly, to the Hungarian Rhapsody, in two years. That is a very steep jump, which many people would take much longer. It does depend on the individual. But I'm just saying that there is a high chance that you will need to work on a lot of basics which may be lacking in ways you don't realize.
I can understand your point of view, but I think that I will be playing it good, probably not as good as the prodigies (who expected that), but definitely better than you think of me right now.
I don't know how you play, but I have a rough guess, if your situation is anywhere similar to mine. I don't doubt you can play at tempo, but there will be lots of points of tension which you will try to use endurance to push through. There will probably be unevenness as well. And you will expect that over time and with practice, it will all resolve itself. It will get better for sure, but it will probably still feel a bit unstable and never fully improve.
Also, I'm NOT Josh Wright, and will probably never be as good as he is, but I will make progress. I also just turned 12 (1 and a half months ago) and I will definitely not give up.
Whoever said anything about giving up? You are still young and have talent, I'm sure you will be able to play difficult repertoire in the future. Some of the best pianists I know started
at age 12. That said, for your long-term development, it is probably better to learn a large number of easier pieces where you can work on a lot of aspects of technique and musicality, instead of a small number of difficult ones played okayish. By all means continue with the Rhapsody if you want to, but try to learn a ton of easier pieces, say one every week or two, and get them pretty polished quickly. I'm saying this from my experience, I have talked to other university students and professional teachers, what often ends up happening is that you can play a couple of showpieces decently well, but it doesn't translate to other pieces you learn. Many had to relearn a lot of technique in college, and wished they had learned all of this when they were back in school.
The reason I give you this advice is
because you seem to be quite determined. And that is a good thing, but you need to put it in the right direction for it to be beneficial in the long run. It's not to discourage you, but to make you think a bit more deeply about what skills you need to develop in order to become a well-rounded pianist.
I actually taught myself how to play the octave sections of the Hungarian Rhapsody, and that too at tempo, after about 4-5 years of starting the piano. I've had teachers react the same way as yours -- you can play the pieces decently well, you have some natural musicality, and they appreciate the fact that they are not going through Alfred's beginner books once again. If you have a certain facility for speed, you can get through pieces, and your teacher will tell you, crescendo a bit more here, this needs to feel like waves, make sure you cross your thumb over here, etc. You will get better, but there will usually come a point where you hit a wall because you have so many inefficiencies in your playing and because so many things are not developed. To put it in perspective, even prodigies have some 5 years of very good piano education before they can play something like the Hungarian Rhapsody well. You have only had 2 years, at most. In all probability, there are a lot of things which you still need to develop in your playing.