To download from the download section, read this sticky:
How to get access to Download Area? - Top Sony Forums

Better bass (mega bass) - can be patched or can be set manually.
Louder sound - louder accoustics can be used
Better music player, walkman if possible - nope it cannot be flashed to a walkman version because there isn't one like it; but a walkman skin patch can be used; to make it look like walkman 1.0.