Personally if I wanted to use my TP2 only as a PMP I would get a titanium only rom (NRGZ28 cook a titanium only rom, it's a little bloated but still very fast. It comes with youtube, google maps and opera browser apps), install a very basic UI to launch various apps like IphoneToday.
I would then install the following applications
-Nitrogen (music player, very touch friendly, does not consume alot of ressources)
-CorePlayer (paid software, plays all non HD XviD natively smoothly)
The following are useful as long as you have a connection to internet:
-Kinoma FreePlay (stream mutimedia content from your computer over the internet or LAN, providing you have Orb installed on your computer)
-Scilor's Groovemobile (listen to grooveshark music)
-Slacker Radio (internet radio streaming)
-mVu mobile viewer (download and stream videos from DailyMotion, YouTube, CollegeHumor... and various pr0n sites
).
If you wish to push things a little further you could also get moTweets for twitter, DroppedBoxx for DropBox access and fim for facebook chat.
You can even try to overclock your device with WinMoSpeed to reduce stutter and improve multitasking.
There is alot you can still do with a TP2, just look around a little bit on these forums and on XDA-Developers and you'll find amazing programs to enhance your device has a personnal media player!