Excuse my ignorance but what's that thing you're developing exactly and how does it help psx4m?
In a nutshell it is an ini reader integration which will allow you to set the keys for the actions - in this way the gamegripper etc can be configured to work.
memory cards work fine for me with build 0.4.2, make sure the permission on both memory set correctly. 0.4.2 run perfect for N900 with some tweak with frameskip and cyclemult and overclock...as typing right now..im install psx4droid on my dell streak...testing the DELL STREAK and loving it...