How would we scale this or potentially 1031 exchange into a larger deal (commercial)?

Seller finance and reverse contingency are some potential options but both are tough to get in today's market, although not impossible.

Potential for increase in rents and appreciation upto 3.5 to 4million in 5-6 years but not sure.Rents at 210k per year for 4 tenants. 50k per year total paid for common area maintenance by all the tenants - which includes property management fees, property tax, insurance, snow removal, other maintenance and misc stuff. 

Is this a potential problem or is this easily corrected?

This sounds like potentially a very good plan

Plus, one of the biggest draws is the potential energy savings, which you typically don't even benefit from as a landlord if the tenant's paying the power bill. 

When you purchase, make sure rents in the area will be a potential cashflow for you in the future.

Your only worry remained getting the correct rate of interest to pitch to a potential investor.You wrote on your profile that you're an insurance agent.

Point out good cities / neighborhoods in the area with good cash flow potential is appreciated. 

This proactive approach protects landlords and creates a safer environment for tenants.Quality Control: Tenant maintenance quality varies based on skill and experience, leading to potential property issues.