1) Use Beta Player (now called TCPMP). You can find it at:
http://tcpmp.corecodec.org/about
2) Dont install any apps to main memory, install them to either BIS or to a memory card. The ONLY thing I have installed to main memory is Pocket Plus.
If you already have things installed into Main memory, uninstall them and then reinstall in the new location.
3) No, but it is only a month old.
4) Dont know
5) Dont know about a free one as I use the Resco Photo Viewer.