A move-in ready place with one side already rented is a great way to jump in, especially when busy with your career.

This is common during negotiations for proposed business collaborations for projects, mergers, acquisitions and selling of a business.

What is your business model?

unless they are in zoning and land entitlement or land development it wouldn't be developers. if they are that's not a design build firm that's a land development company. make sure to understand how they earn their income and how they come in. how the earn their revenue will be more reflective of what their business is than what they say it is 

I use a simple 1 page purchase agreement that is assignable, I put a 60 business day close, and I have an assignment of contract that I use to sell it.If you would like them, I would be happy to share.Good luck.

Which will bring plenty of other investors and general business to the area.

My business partner and I have started to looking for deals for fixing and flipping sfh.

All work, no pay.If you want to make money, stop trying to chase get-rich-quick schemes or working with shady businesses.

I've had businesses for years dealing with credit card payments and refunds are simple. 

@Claudio Garcia Zuniga If you are local to the property and only own a few of them it probably makes more sense to manage them yourself if you think you have the capacity to run it like a business.