I want to know if a sale agreement offering the buyer (renter) the option to buy the home after 12 months a valid/legal contract in the state of Michigan.

I am not sure where you are but here in Georgia any judgments are supersede by the bankruptcy and as @John T. stated the tenant has an automatic stay from eviction.

Definitely look into your states DPA programs.

Some hard money lenders want to see a bank statement and will ask for a letter of explanation if they see a large deposit, others wont need to see a bank statement at all, in fact we would only need a stated personal financial statement.

I am an out of state investor looking at San Antonio for investing in multifamily . 

Florida has just passed a state law defending landlords against squatters! 

As an individual, it is hard to open an efficient, responsible, profitable out of state network because as an individual you do not provide that much value for an agent or a contractor to run around and cater to you.But when you are part of a group that closed on over 4 million in real estate in six months and brought in over one million in local rehab dollars and put 50+ people to work and paid the city inspection office for all the permits, inspections, and reports then people cater you to. 

If you google, "how much are closing costs" you'll get a result from Rocket Mortgage (most expensive lender) stating the fees could range from 3-6% of the property's value. 

The house is in a bad state on the inside, but she will sell it to us for around $50,000.

There are so many so be sure to filter by your location. 4) Review Dave Meyer’s The State of Real Estate Investing Report 2024 (in your resource page as a member of BiggerPockets!)