I can't do the EGR delete because of emissions laws where I live. 

As mentioned above in this thread, I think the problem of emissions Is greatly reduced over time.  

Do you know what the low emissivity coating and the argon between the panes actually does?

You can either reduce the amount of carbon emissions or “sequester” more carbon out of the air.1.  

By reducing the energy consumption of the HVAC system, greenhouse gas emissions can be substantially decreased which helps show your company’s corporate commitment to being environmentally responsible.When you are searching for the best energy-efficient HVAC system, here are some technologies and design principles that enhance performance:Heat Recovery Ventilation: Specialized units like energy recovery ventilators (ERVs) capture heat from indoor air that would normally be lost.

Most oil burners are 82-85% efficient and need annual maintenance or that efficiency drops substantially. plus the emissions aren't as good as gas.

If energy-efficient or modernized homes are in demand, this upgrade could make your property more competitive.Environmental Considerations: Gas logs are generally more environmentally friendly than wood burning, as they produce fewer emissions.

Emissivity(E-factor), Polarization.....

Though I also see the benefit in new construction, it could appeal to tenants who can pay more and the building will likely not need much or any work for several years.Those other updates are good ideas too, and not overly expensive, like adding mini-splits, convert to gas (though I hear that natural gas is falling out of favor now due to gas emissions and the environment), or connecting to public sewer (though I've been looking at a lot of urban and suburban buildings that are already connected).

Section 3 states the we will have to reduce our emissions by 50-95% within the next 40 years.