1. Yes, it's 5 Ads.
2. Anything, including equipment, zeny and inventory, that is on the individual character will be transferred over. Nothing in storage, however, will be transferred.
3. Character transfers are currently down - You will not be able to get one done until the service is available again. Normally though, they are done within a few hours to a week.
4. No, you will not receive anything about their information, and they will not receive anything about theirs.