First of all... Wecome to the Forum!
Let me address your questions one by one.....
1) not to jeopadize my U.S. citizenship - You will need to relinquish your U.S. citizenship if ONLY you acquire the Indonesian citizenship.
2) stay long term in Indonesia - How long? Since you mentioned that you will still need go back and forth the U.S. there are 2 options depending on your length of stay....
option 1 - SosBud (Sosial Budaya) visa - offers you a 60 day initial stay which is extendable up to a total of 6 months. No Work!
option 2 - ITAS (Izin tinggal terbatas) ikut suami (husband as sponsor) - offers you to stay for a whole year (renewable annually w/o going out of the country) BUT strictly NO work allowed.
option 3 - ITAS (Izin tinggal terbatas) company sponsored - offers you to stay for a whole year (renewable annually) and work on a very specified role. Need to pay US$1200 annually in tax and the specified job must not be one that can be performed by an Indonesian. (several other restrictions do apply).