I struggle on the sax above high D. I don't plan on learning it because I'd never need it in church. I'll stick with d and below. If I can find some alternates, then up to high f would be okay. I may get there one day.
Flute is really coming along. I know all the low notes, but just have issues with the initial attack on the lowest 2. Higher notes will come as I need them. Still enjoying this instrument a lot. In a few months I may make this my main instrument at church.
I know my music director, he will want me to stay on trombone, but I think the other trombone player would enjoy playing an octave lower than he has been.
I am going to snag a flute book from church and see about doing a duet with piano one day. I did just order an exercise book for flute, and from what I've read, pros even use this book still. I'm going to practice it from it every day.