We have used this attorney for more than a decade and have a grandfathered rate.

@Priscilla Shu it is OK to keep going if you are doing it in a legal way AND you have appropriate reseves to fund you past problems. 

Should we open a new bank account in the name of the LLC that the other partners would fund?

You need first to verify they are okay with this.You must be very careful since if any investors are "passive," it becomes a syndication, and then you must consult an SEC attorney.It sounds like your investors will pool their funds together (they probably will create one LLC) and become a 2nd position lender.

Does anyone have, or is anyone aware of a calculator with inputs to show me whether a seller paid 3-2-1 rate buy down vs price reduction is best, where I have ability to input for how many years. 

So maybe you could try to find something like that and do Airbnb in the meantime.Subdividing is not super cheap, and vacant lots typically sit on the market longer than homes do, but it could be a good opportunity if you have funds available to purchase the lot and to pay for subdividing services.

Have you hit your goals or exceeded them, or are interest rates and low inventory holding you back?

Multiple books: The Book on Rental Property; The Book on Investment Property Investing; The Book on Investing in Real Estate with No (and Low) Money Down; Start with Strategy; Real Estate by the Numbers; and Finding and Funding Great Deals.

SFH with %8+ cap rate.

While housing is objectively more unaffordable with current prices and interest rates, when will this be reflected in the overall home ownership data?