@German Fernandez Love those options!

The condo will limit the rental options to age restrictions. 

With a family and kids the best house hack is a house and cottage or duplex option.

Gas or electric would be a much better option, safety wise, from a house fire standpoint, CO danger, or danger to children or pets from the open flames. 

Would a home equity loan be a viable option in this situation, especially in regards to eliminating some of the red tape I'm running into with a refinancing an scorp-owned property?

I've been at this a while and have over 70% equity in my combined portfolio, and I'm over 50 years of age, so I don't look at creative financing options. 

The agent turned down a seller financing option - although it was not ran by the seller - because the agent said the seller is so done with the property that she wants nothing to do with it at all.

BIG bonus is you snag something with Timber that will grow and you can do a selective harvest 20 years from now the Timber could end up paying for the building of the home.

This might give a one-time (non-scalable) boost to cash flow, offer multiple value-add options, and allow the house-hacker peace of mind, via the assumed mortgage, in long-term breakeven or positive cash flow in the event that the value-add plans end up not being executed, and/or the person has to move out, and rent by the room or STR become unavailable for some reason at a future date.

OC California is very expensive so investing out of state can be a good option.