I love the pieces and love the program, but I'd tweak that order. The main thing that strikes me the wrong way is following that Beethoven sonata with the Chopin Octave Etude. I think the etude "tramples on" the sonata, especially considering how the sonata ends. I think it ruins the mood that was (hopefully) established, and I think the ordering seems almost like it shows a lack of appreciation for what the sonata is. But of course that's subjective, and I'm sure a lot of people would think that order is fine.
As a lesser concern, I wouldn't start the program with the sonata. The feeling is maybe ironic on my part, because back in the day (I'd admit that this was for the Beethoven bicentennial but I'd be sort of admitting my age)
my college did a Beethoven sonata cycle, and they led off the series with that piece (played by me, no less).
But while I think it's a great piece to begin a sonata cycle, in general I think it's not best to begin a usual kind of recital with such a relatively long piece. That's another thing where I know that lots of people would think it's totally fine to keep it as you have it, but I think it's usually best to "ease" the audience into the program with something shorter. Of course you could say "but the sonata is 4 short movements," but still. The audience doesn't get to applaud or to stretch that much in between them.
And for just about the same reason, I think it's best for most of us also -- us as performers -- to start with something shorter. But on this part of it, obviously all I can really speak for is myself. I'm just guessing about others.
Putting that all together, here's how I'd order those pieces:
Schumann: Arabeske Op.18
Beethoven: Piano Sonata Op.26
Intermission
Chopin: Etude Op.25 No.10
Brahms: Piano Sonata Op.2
