Once you take over the cabin there will be other unexpected items you will need to purchase no matter if the cabin is new or old.  

It's had some tenant drama, one eviction, and plenty of unexpected expenses.

It's not a common thing that people go through when a tornado hits your house unexpectantly and having to do a total renovation.

Many alternative lenders have internal guidelines that prevent against lending on assets with any commercial components.

It's been a good experience, very eye opening for me as well as financially nice, and of course, there have been unexpected issues (ie, no matter how sad a situation seems to be, have a 1 strike late payment policy!)

Before that purchase, it might be wise too consider having some operating capital for unexpected expenses set aside that is liquid cash well cash equivalents.Good Luck!

How do you manage cost, unexpected surprises and keep the project on time. 10% to manage a rehab is actually pretty cheap, I suspect you have never done that yourself, otherwise you'd know how much work that is.

@Zac Kucharek  I will focus on the asset protection component of your post since it appears to be the primary objective.  

That said, Solo 401(k) with Roth component can be powerful and does open up the discussion with your CPA or tax pro about paying yourself more (within reason), in order to make higher contributions. 

It can also promote mitigation planning as well encouraging back up resources in case of the unexpected.