First, see my reply to a related topic on this board - http://www.cruiserlog.com/forums/top...?TOPIC_ID=1732
I think that putting a new boat on charter will make it an old, worn-out boat very, very quickly.
There were some expats in Phuket, Thailand who were managing other people's yachts, though I don't know much about it, and my last contact was several years ago. I d not recall any sort of infrastructure in Singapore to support chartering your boat there, and I wouldn't leave my boat in Indonesia. I don't believe you could find any reliable caretakers in indonesia, and since Indonesia only grants a 3-month cruising permit, (unless you could set it up in Batam), what would you do to avoid heavy fines and other hassles? I did not like the marina in Batam, it is exposed to the north and when the swells come in your boat is vulnerable to damage - particularly so if you're not on it.
I just don't think it's a good idea. I'd welcome other information from people who are in the area now, though.