Get a Non O from your country even if you are only here for a few weeks. Make it easier to get bank account. No idea what it will be like trying to open one in December. Its already changed a lot since last december till now (more enforcement of existing rules)
All depends on the insurance issued from your country some have limits of say 100 days. Some say longer but then you read fine print and a years insurance may only be valid for 60 day stints at a time.
Always a good idea to step back and look at situation before jumping in. Been here a long time seen many succesful buisnesses but seen hell of a lot of rip offs and scams also.