Contractors all the time either fail to finish or finish in a way that prohibits you in selling and exiting or refinancing at the number you expected and now you have to leave way more in than you thought. 

Depends on the contract language, but under typical language the seller is obligated to the sale if all contract terms have been met, and the jilted buyer can usually get a legal block prohibiting the sale to another party.

But for most small units off beach that may do $30k it is cost prohibitive and I have never seen one that fully offsets cost of utilities and some maintenance. 

Doing so could be considered a form of illegal eviction or "self-help eviction," which is prohibited by law.

I shake my head at the 1/4 mile restriction because the idea that you can be prohibited from doing something with your home because one of your neighbors is already doing it doesn't seem right to me.

Legal ConsiderationsFair Housing Laws: Ensure your reasons for denial comply with the Fair Housing Act, which prohibits discrimination based on race, color, religion, sex, disability, familial status, or national origin.

For example, if a state enacts a law that prohibits individuals from having boats on their property, the state would then enforce that restriction.If the restrictive covenant governs an entire condominium building or a subdivision, they are enforceable by one or all of the property owners in that community.

I’m also based in Miami but invest in other states for similar reasons—Miami prices can be prohibitive for getting the returns you’re likely seeking.1.

You're treading in RESPA-infested waters there and these are federal, not state regulations.Referral fees for ANY closing services on residential loans are strictly prohibited under RESPA regulations. 

So, the answer is: there is nothing that clearly prohibits DIY cost segregation reports.2.