I normally move all the files, lib and davlik files. I think I had one app once that didn't like this but never had a problem overall. Some apps have lib files as big as the apk itself.
PS: is it wise to include lib files when making the link? Seems like default is to keep them in /data. Does this matter?
The partition will stay as ext4 through a rom flash unless the rom specifically changes it but the link2sd and modded install-recovery.sh will need installing.
does this need to be reflashed with every ROM change ?
In short, yes but it could be done manually if preferred.
Edited by Cyda, 13 November 2012 - 10:30 AM.