I'll let you know how much it will cost; then you can let me know if you want to proceed and I'll send you a lease addendum to e-sign.

You can expense property taxes and loan interest on your Schedule E. 

We wore masks because of COVID, and when we went outside could still smell cigarettes/nicotine through the mask.

A quick-and-dirty valuation of 16X earnings (average P-E ratio of U.S. stocks) would put the value at nearly $1MM.

This may be moot if he needs to waive something for the deal to proceed.Where it comes into play (I've seen it before), is if the buyer made some E/M non-refundable prior, then I'd think he's lost that non-refundable if buyer doesn't perform.Again, we're missing the original PSA for terms.

If she never met the landlord in person, then she would have e-mail, phone number, text messages and similar evidence.

While it is real estate related it’s more of a financial services.I have E and O under debt collection licenses but I do not believe that will cover me if I get sued by someone I sell a note too.

Your best source to determine what it would take to separately meter the gas usage would be to talk to the local utility company. 

We have an existing business in the countertop fabrication business and need more space to get the automated equipment we need (water jet and line polisher).existing facilities are not what we need (10k sqft warehouse, 1500 sqft + show room (separate or together).we want to buy as we own our current two warehouses (2 units 4k space each).strong reinforced foundation (ideally gently sloping to remove water), 20 ft+ ceilings, 2+ loading bays, low HOA (or water and heavy granite/quartz trash removal included).because this is so large and specific and e-commerce has jacked up warehouse prices we are strongly considering building. 

I would include electric in the rent, and write a usage allowance into the lease, say 400 kWh on average, and adjust quarterly if needed if tenant's usage is over that value.