A high property tax rate will increase the taxes more quickly as a percentage of total expenses when the property value increases.

The maximum fixed-rate period seems to be seven years, and there is generally a balloon payment at 10 or 15 years.

My firm has several lenders who can seamlessly close in 15 days on 'traditional' mortgages at/below market rates and we've been doing so for a couple of years now. 

Some costs MAY qualify as startup costs if the rental rises to a qualifying trade or business level under 195 as well.

They could self manage for several years, using the rental income, until the next phase of their retirement.If they have a decent amount of financial discipline, they may want to get a HELOC now before they build to get the most favorable rate.

Refinancing: If the lender doesn’t approve, refinancing under the LLC might be required, but LLC loans typically come with stricter terms and higher rates.3.

Although 3.1% is a great interest rate I tend to not get too caught up in keeping a property just because the rate is good.

I started off doing long distance BRRRRs until the rates went up.

Also I've heard of some DSCR loans that are not too far off from conventional rates.  

If he must attempt to get the low interest rates of 2021 on this deal, I suggest that he instead look for assumable loans.