So even if there is a temporary slowdown, once the overblown mass hysteria dies down things will likely return to normal with a bunch of pent up demand that's been shut in doors the previous few months.After all, it's not like housing demand is suddenly going to go away.

Can I buy a normal single family house that is 3 bedrooms and rent it out to my friends while I live in it and it be "eligible" as a house hack?

I would not normally consider this strategy.

How to adjust to the new normal?

Rates decoupled from the normal co-correlates weeks ago.

During normal times (the virus is not normal times), I would think 5% long term appreciation is not aggressive, but I would choose more conservative of 3% or 3.5% in my projections.  

Assuming you have a 'normal' DTI and aren't the CEO of a Fortune 500: She will need to demonstrate that she alone, without your help, has been making the payments for 12 months, before you can realistically hope to get a mortgage.Assuming pre-covid mortgage guidelines.

If they are moving out, you do an inspection AFTER they have moved out documenting anything that is not normal wear and tear (take photos). 

Does anyone know if depreciation from cost segregation and bonus depreciation is treated the same way as normal depreciation or if it is taxed differently?

@Tchaka Owen - HELOC would normally be great advice but those were the first things being cut when the market started to tank.