You can size it down to as low as a 150MB system and 2MB cache
As for Skype:
Go to the advanced options and select to enable MODE_IN_CALL.
I've tried to fix the Gingerbread bug in the past but as the libs aren't open source then it's near enough impossible to do. Theres some stuff at the framework level to play around with, but because Dolby is there it complicates things even further.
It's getting there, but there's still much to do. The icons are the biggest challenge.
download this, it's a icon library, hope this help man