Export of ratings is easy since there is an IPTC field for that. Import from that field would work as well (but the app is not set up to allow synching of ratings – for example, if you change the rating in another app, RAW Power is not set up to check and update its internal rating. Flags don’t have a home in standard metadata (AFAIK). There isn’t a forum for feature requests; people just post in the help forums or email support@gentlemencoders.com.