Gymastic back is a problem for skaters; the landing position in gymnastics is horribly incorrect for skaters, and it's hard to eradicate. On the plus side, it does build core, flexibility and upper body strength, plus musicality, and general athleticism. One of our competitive skaters is also a competitive gymnast, and you can definitely see the problem on the ice.
Ballet CAN be fun! My DD loves it, and it does build carriage and posture and musicality, leg strength, extension and balance. I think you simply have to find the right teacher and the right class. Skating has certainly improved - and the focussed training has spilled over into other areas, as we've noticed more focus and persistence elsewhere, including school. We also enjoy the poise and gracefulness she has in general; and, naturally, the manners that a Russian ballet school insists upon are a good support to our expectations in that area.
Our ballet teacher does discuss skater's foot though ... apparently, back in the day, when skaters weren't put into stiff boots, they were able to achieve toe point and foot extension more easily; now, with stiff boots, she's finding more and more are struggling to get a properly flexed foot.