Wrong, Perry Mason, the injured party will sue you in the state where the accident happened even if you have an out of state entity and you will have to comply with the laws of the state where the accident occurred.

Several have been killed and many injured.

That lawsuit is a claim for fraud, and that’s what fraud typically is...a misunderstanding and someone being “injured” and wanting to hold the other responsible for it.

If you do insure it on a separate policy, I would recommend using the same company as the could be a question of what policy responds if someone gets injured outside of the unit. 

I'm not aware of any renter's insurance that would cover damage to the property itself - most policies cover the tenant's belongings and may include liability coverage if the tenant negligently injures someone on the property, for example. 

If the contractors and the workers get injured when renovating or flipping a house, I will be responsible for all their medical bills.

People get injured, die, etc)What happens if he can't come up with the ongoing costs of a project?

What if they "injure" themselves while doing work on your property?  

From legal standpoint, having property in a company offers some protection from outside, non-real estate-related lawsuit judgments (think a person injured when you drive intoxicated, when your auto insurance isn't enough and they start hunting for other assets).

It names you as additional insured; covers their belongings and some liability if someone is injured.