Here is new version with some of the pending requests:

changelog:
- some options changed to strings (thanks jabawok)
- new button to apply the settings directly, those will last only till next reboot. Persistence button will save the file and the tunings will survive through reboots.
- addition of VFS Cache Pressure option (has been left by default unselected).
- some rearrangement on the gui to fit options.

Please report possible issues.