Learn from your problems to prevent. 

I'm sure you are asking more along the lines of how you could have prevented this or how you can prevent it in the future but it sounds like the handyman messed up when installing the wax ring.

You might want to lean how to perform a title search before spending too much time only to find out he has some baggage preventing him from selling.

That creates air flow which will prevent future mold and prolong the life of the new roof.

Essensially I will purchase my own property but would my DTI, since I’ll be in my moms loan and my own at this point, prevent me from getting cash out during refi? 

They may be able to talk to you about common problems and how to avoid them, as well as your state-specific law.An ounce of prevention is worth a pound of cure!

No amount of experience will prevent that.If you're not prepared for a $30,000 rehab over budget, either don't do the deal or do the deal with someone who can manage the rehab, bring in some skin in the game and will get a portion of the cashflow and the profit when you exit/sell the property.

If I do decide to sell, are there any ways to prevent/delay the gains from being taxed, if rolled into another property, or something.

Sure, it's unlikely to be A class property, but as long as it has been renovated and the major systems (foundation, roof, HVAC, etc.) are in good shape, it wouldn't prevent me from pulling the trigger.

@Tony Castronovo @Vijaianand Thirunageswaram @Michael EalyIn case you weren't aware, legislation will be passed in Texas later this year that is aimed at preventing this type of deals.