They have formed the Rental Housing Coalition that is doing great work lobbying on our behalf, regularly updating legislative activity, giving talking points and providing simple ways to contact your elected officials and committees. 

Preferably with a link from an official source?

The son is wanting his dad to sell because his health is on the decline and cannot travel.

I would say to find out officially. 

It is your decision not hers.Submit it at the price you value, be polite, let it expire officially but let the seller's broker know you will still be interested if it doesn't sell. 

Health insurance providers are operating at the state level.

The third factor is the pandemic (and the resulting public health measures) has given potential buyers a new sense of urgency, with demand for existing homes so strong in December that 70% of the homes sold were on the market for less than a month.

Can I leave one side of the duplex empty for me, and change my official address to it as well... without physically being there very much?

I assume that for:Title/deed to the property which the title company mails after closing -- the county maintains the official record, and I assume this is a just a photocopy anywayInsurance policy -- you can always go online and get thisLoan and purchase paperwork -- as long as you have a record of your closing disclosure, all the other forms you sign for buying/financing are mostly fillerCurious to hear what others do with all these dead trees.

Normally, FHA requires the seller to fix things that pose "health and safety" concerns before the deal can close.