My ultimate goal is cash flow to be able to quit my job (self-employed) and focus on real estate full-time.

Schedule a job walk at the project site with your architect present, at a predetermined time and date. 

What you need to understand is that you'll have to disclose two things in your offering document:1.

I'm getting really tired of hiring ****** professionals who can't do their jobs properly. 

We have three offers for them, and I would like to present this information in the best way possible.

Then offer him a deal for $1500yr to keep it green instead a tractor storage facility.

It's a 4 bed 1 bath and I'm open to either renting it or selling it (if I'm offered a price around the ARV).

They are probably including the roof in the price of the solar panels, and they make it enticing by offering installment plans.

Today I was approached by someone who is offering me around $1800-1900/month to rent the property from me to run a short term / medium term rental out of it, primarily for traveling nurses or other business people.

NICE GUY" and if necessary, you can and will take different routes. maybe offer $50 gift card for the inconvenience and keep things in good term but you should stay firm and sound more entitled.