Thanks for the vote of confidence jstar!
So I'd agree with snpark about your visa....rather than jumping head first, really take a deep breath and try out the VOA first, if 30 days is not enough try the extendable up to 60 days total (and watch the need-to-leave the country deadline very closely ). Again--my knowledge of the visas and its development is limited and can be outdated.
Once you're here, I assume you have friends/family? Don't make big announcement yet to everybody you're a US citizen, coming 'home' etc etc just pick a few trusted ones to share what you need. Many Indonesians fall into more of the 'kepo' category and you'd spend lots of time answering questions than getting answers!
Second choice of visa...not sure if the sosbud visa (the 'family visit') is still available? if it is, you'll get more than 30-60 days in the country (like up to 180 days/6 months), but I used to know one or two expats who just did what snpark mentioned...voa...then every 60 days a quick 2 days visit/short vaca outside Indonesia, then fly back in apply another VOA. I hear the airport immigration (depending on your luck) kinda frown a bit at same day in-and-out of indonesia just to apply for another VOA. I would think after hanging out within Indonesia with 2-3 VOAs you'll get the idea what to do a bit better.. and I understand this from living in the US for half of my life (at that time) and being here for quite a few years, it is important for you to keep balance between our American mindset and how people do things here in Indonesia..
Banks: Not sure about now, but I think while they might let you you open a bank without NPWP (again- maybe not recently), they will require at least KITAS to open one...so if you're on voa, i don't think you can open a local bank account...(like BCA), but a few of my expat friends have been living here for years (english teacher, engineer, etc) and they always use non-Indonesian cards, some even until they finish their job and left Indonesia. If you MUST have a BCA- maybe have a really trusted family member open a BCA account, you hold the debit/atm card and the token...and you can use it to transfer, withdraw money...not sure about QRIS set up btw (good to have if you really want convenience). Again- no judgement here, just saying this is what some people have done.