I would not sign a lease and buy a bunch of furniture to potentially make $350/month. 

Couldn't agree more with replacement costs... a lot of BnB-ers trash your furniture.

Landscaping has the largest ROI (of about 200%), adding a wood deck or a patio will also provide a big increase in value (100% ROI).Add living space, consider converting attic space, finishing a basement, or repurposing a large living area to add a bedroom without expanding the home's footprint - this will give you an average ROI of around 75%.

He can also leave any furniture behind and we will clean up.2 – Flexibility to close/move in on date at his convenience.What other suggestions should I make to make my offer better?

But you may be able to do option A for $10k or less in setup & furniture, esp if you buy the place fully furnished.

The restaurant will have a 1500 ft2 patio as well as the 3500 ft2 indoor space to finish out the design.  

Total cost was103K hipoteca44k downpayment and works + furnitures  

Most people looking for a one-year lease have their own furniture.

@Ryan DaultonNot a specialist in this but I was told I could not spend a penny of my personal money or sweat on this whether it be furniture, a light fixture or anything and that seems to be in line with the comment above

So I am looking to put in a patio and a space for a shed to anchor.