Ned Rorem's Etude No. 7 is for right hand alone. It is very difficult and will keep your busy. It isn't too long either. Also, it's not an etude, but York Bowen has a piece called Caprice, for the Right Hand Alone which should suit your purposes.
Want me to write/transcribe you a piece for the right had alone?
these are not etudes for the r.h alone but do focus on the r.h:chopin op.10 no.1,2,5,8Liszt transcendental etudes: Feux Follets, no.1
I know the alkan 16 minutes etude, but that one is too long and "boring
No.
Yes
No. It's not quite Alkan at his best and, at times, it seems to be a little contribed and at other times almost impractical (which Alkan rarely is, even when writing his most challenging music), but boring? - never!Best,Alistair