You typically charge them an Option Fee (the $20k) to lock in purchase terms today. 

In terms of rentredi though, I can say I've used it for about a year and a half on my three properties and have really liked it. 

BUT regardless of that, the numbers should still match your original term sheet!

For those using a LLC to acquire fix-and-flips, wholesale, or deals you don't anticipate holding long term:Are you utilizing your home address or a virtual business address?

Do both of yourselves a favor and give it a long lead time, that way they can come to terms with the new rent and make adjustments to their budget, and if they are moving out, you both have time to get your ducks in a row (you to try to do a fast turnaround on the rental) and them to find an appropriate new home. 

Why do you think purchase contracts are so long and have such small print?

You have to follow the required eviction proceedings  as required by Texas or she will be in the house living rent free for a long time. 

Unless you can come to terms with this individual; eviction might be the only route, and that might be a tricky process with someone who "knows their rights" my buddy recently had an issue with this, and it took him over a year to remove the tenant.

The guest said she was house hacking but only stayed there in the property 6 months out of the year and short term least it out the winter months to travel and stay where it is warmer weather.

Also, in terms of flooring for the storefront what material would be best in terms of money and quality?