No harm, except to his credit.

Your goals and outcomes in life are nothing but compounded habits.

even if they did, likley no harm at least as I see it.Take the booking and get a great review, pocket the cash and move on. 

On the positive side - once it is habitable you should be able to quickly re lease. . 

When you work in any industry you pick up habits and tricks that make the work or product better. 

.- “Landlord is required to supply at all times during tenancy…a unit in a clean and safe condition and the premises in a habitable condition…"- "Uninhabitable - ...Defects or conditions ... unhealthy such as cockroaches or mold..."

The mindset of changing your spending habits to investments rather than liabilities for the rest of your life is all that you really need to be successful in this.

The mindset of changing your spending habits to investments rather than liabilities is the key.

Are there trees over the house that could harm to house?

Once you know what kind of tenants you have and their living habits and periodic inspections of their unit, you get a good feel for things and a good estimate of what you will be doing in repairs and improvements over the years.