since you have the chance...
Make yourself a Pandora Battery and a stick '
its allways good to have a backup should the flashing fail
its a good idea to format the MS before, maybe you should even use the 'original' one that probably came with the PSP you dont need more then 32 MB for the recovery.
for the Pandora i belive you need more space.
while writing to flash nothing is 100% secure (more 99.9%
).
But using the pandora bypasses the flash
And, i am sorry but i cant reccomend a media player
i always loved PSPRadio as a shoutcast player
PMP is very fine but i dont know anything about its subtitle format
PimpStreamer never worked realy good for me but that can be because of my accesspoint.