A bathroom, kitchen, or basement remodel will not qualify for the De Minimis election as a whole, rather individual components and personal property will qualify for the election. 

If they get into a scrap and he leaves, or gets put out, you could simply lock up shop and put the burden on her to go to court to force you to recognize her de facto residency, rather than you trying to figure out where he went and whether you can get any money from her. 

You might see if there are any such interests on the secondary market that you could identify and buy.Purchasing Tenant-In-Common interests, Delaware Statutory Trust beneficiary interests, Land Trust beneficiary interests and other "disregarded entities" qualify for 1031 Exchange treatment, but Section 1031 of the Internal Revenue Code specifically excludes any kind of partnership interests for 1031 Exchange treatment. 

I will say this is the least attractive of the three safe harbors as the De Minimis Safe Harbor (DMSH) and the Routine Maintenance Safe Harbor (RMSH) will likely yield better results. 2.

It looks like under the new De Minimis Safe Harbor rule I could just deduct the full value in that year. 

If you are put your mind at ease, lawsuit abuse is an urban myth propogated by the republican party in an attempt to "de-fund" the democratic party of the contributions they receive from trial lawyers.When you buy a rental ppty you insure it under a Fire and Extended Coverage (EC).

If you set up the entity in NV or DE other states will force you to register as a foreign entity.

Being a Registered Agent in Delaware, my answer is going to be somewhat biased, but I'll try to remain as objective as possible. 

@Stanley Okazaki Not sure what your screening process is, but there were a few good suggestions you should use moving forward from @Dan Perrott and @Alberto De jesusYou should also have screening criteria somewhere in case you're accused of discriminatory practices.

Did they care about your $150/hour moving company idling in the cul-de-sac?