These will be LTRs and I will most definitely be playing the long game with these.In addition, as rates go down in the future (hopefully) I plan to refinance as most of us do.

. - 30 year fixed terms - Usually have a Prepayment Penalty from 1-5 years, although you can price out a 0 PPP for a higher rate or fee- Minimum Credit score is 650 usually, although you could do a lower LTV loan at 620. 

How about the interest rate - is there also a different rate for citizens and non-citizens?  

While not impossible, you'll be paying a much higher interest rate for the loan than with 20%+ down and also you're likely paying some points or splitting the profit if for resale. 

A cash-out refi isn't really appealing with the rates and I'm locked in at 30 yr, 4.7% currently.

That is the best option if you are truly trying to help a family member.you cannot get control of the mortgage, you can do sub2 but you are not in control, the bank could call it due if they see the property transfers title.The other way is for you to buy it from them at market rate, then rent it back to them at market rate.

The rate the manufacturer offers is 4.8% which is why I am going through them.

Congrats on your success in acquiring the duplex that now will yield 6.5% cap at current lower rental rates. 94115 is a great zip code to be in.

It really doesn't apply as much anymore in most markets because rates are too high and homes are selling for too much. .75% rule is more viable and would be the new 1% rule in this market.

The real estate market has shifted dramatically in recent years rising interest rates, evolving buyer and seller expectations, and fluctuating property values are keeping all of us on our toes.