My son is our real estate agent and it's his first deal ( we're his first customer!).  

As a new real estate investor, you should start in your own back yard where you have the advantage of first hand knowledge of the market, the customs, expectations, laws, and a network of friends and acquaintances who can help with advice.  

Customizing your message is going to work fine for you.This brings up an idea, perhaps BP can "certify" a Pro Account user who has been on the site for at least 12 months and has a clean record.

The answer depends on the speed you can get a simple, professional website with basic information and a fillable form to capture customer data.

Instead, think respectful and professional interactions, open and honest communication, prompt response to tenant needs, establishment of good property management systems, and customer service. 

If you are an electrician and you charge $75 an hour nobody would chastise you for turning down a job offer from a customer who wants you to work for $12 an hour.

In addition to the energy savings the customer will have (more $ they have to pay rent), another perk of tankless units is lifespan.

and how does your company sustain overtime with these "lifetime" warranty as if the customer experience any problems with foundation, you will be called and you will have to provide the support. 

Your handyman is probably working under a standard business license, which forbids being paid or accepting payment for more than $1000 on any job or for any customer in a given year.

So I assumed they don't need new customers.