Or is there some consulting contractors offer as part of their services.

Consult a lawyer who's familiar with residential leases in your area.

Consult a professional on this one.4) HELOC: If you have a property already with some equity, taking out a home equity line is great for low interest rates5) PLOC: This is similar to a HELOC however since it's a "personal" line of credit it is not secured debt and tends to have higher interest rates.

If I were you I would consult with an estate/probate attorney and see if you can't draft a new sale with the surviving children.

However, many people that I've consulted with say that deposits are just that.

We also did extensive renovations so we will definitely have to consult a CPA. 

For an idea of cost, to replace a roof to a 1500sf footprint, could be between $12 & $15K.Property insurance is an expense that none of us like, but at least know, or contact a professional to consult.

@Ramiro RodriguezI use the contract provided by TREC, 1-4 Family Residential contract. https://www.trec.texas.gov/  You may want to consult with an attorney to see if any alterations would be needed to that contract, based on your business model.

Always consult with your attorney before you rely on the above information.

You need to consult professionals about it.