I can't really afford to cover their rent because I will need to replace my dad's income, if he loses his job due to coronavirus. 

Well I think it is obvious you have to be able to afford it.

I cant' seem to make my mind up and figure out whats most needed and what is sufficient to what i can afford. so the break down from several contractors. 

I heard a news report this morning that a lot of restaurants have converted their wait staff to delivery drivers, affording the clientele the ability to still eat their restaurant food and keeping the staff employed.I don't know, maybe I'm being unrealistic but I feel that this is going to be a temporary situation that will resolve itself in 3-4 months... assuming all the drastic measures to mitigate the spread of the virus are effective.

If you and your family can afford to still live as comfortably as you need to in the worst case scenario, then factor that into your decision and move on to the next point.

They might not have the budget for a STR on par with our normal rates, but perhaps at a significantly reduced fee, we can at least get some incoming cash flow to go towards the mortgages, and they get a clean, private space that they wouldn't have otherwise been able to afford. 

I've heard owners offer deferred rent over the remainder of the lease, tenants forfeiting security deposits - if you can afford it waiving rent would be a kind gesture, but that move might not encourage financial responsibility on their part.   

(Note: I am not against affordable housing at all, simply an observation)Like you mentioned reserves are needed. 

Tracy was an area in that I could still afford.

where would I go to learn the process of building affordable housing