1) Yes, still relevant. The SSDs make your physical i/o much faster, but performance will still be improved by reducing the number of physical i/os you have to do. The better the data is packed into fewer pages, the less i/o has to be done.
2) Yes, fragmentation is still applicable. Even though logical i/o is generally much faster than physical i/o, fragmentation still affects performance by requiring more i/os to access the same data.
The recent ASE features involving compression work to improve performance by cramming the data into fewer pages.