Set aside 10-15% for unforeseen issues.  

Depending on how intense and unforeseen issues, that can bite out a huge chunk of 50k alone.

Responses in this forum points out that these requests should pertain to unforeseen issues, and I would see 3-5 years left on the roof would be 1 of them, though everything is subject to each person's interpretation. 

The bad news is it’s tough to know when it will burst, and bursting happens quickly and due to unforeseen reasons.

The only hesitation I have is taking the risk on reverting the progress we've made with getting out of debt, especially if I were to loose my job or other unforeseen circumstance.

Conversion to a Roth can make sense for any number of reasons unforeseen presently, such as tax changes, family issues, etc.  

Sometimes, even the best tenants who are well-screened will fall into unforeseen circumstances.

Even if you haven't lived in your home a total of two years out of the last five, you're still eligible for a partial exclusion of capital gains if you sold because of a change in your employment, or because your doctor recommended the move for your health, of if you're selling it during a divorce or due to other unforeseen circumstances such as a death in the family or multiple births.

We fortunately did not have any major unforeseen things come up with it.

Either way, make sure your partnership is structured to cover unforeseen problems.