You need to really learn the laws, have a solid lease, and have policies and procedures in place to deal with the difficulties likely to arise.

when the need for me to move in there might never even arise.... so how might I word the clause? 

Well, evidently, and this is actually in their contract, "if a drainage issue should arise" your LIFETIME warranty is denied and you are on your own.  

The best market for fix and flip is in a rising one. 

They don’t realize that an investor or real estate broker who knows the true market value of the property may be taking advantage of them by actively misleading the homeowner as to the true market value.The problems arise when the investor or real estate broker:Drives down the property value in the seller’s mind by showing them comparable properties that aren’t really comparable.Talks to the homeowner about all of the deferred maintenance that the property needs (which may or may not be true).Allows the homeowner to leave items behind (What is that “convenience” worth - the costs of renting a dumpster, hiring two-three workers for a day to unload your house?

Not worth the stress or any problems that might arise IMHO. 

If subleasing is an option, have him put something in writing so you're protected if the situation arises. 

., more people can afford more house) which in turn caused the increase in prices.If the foregoing is correct, then it follows that real estate prices might fall due to a rise in interest rates at the same time that rental rates are increasing (i.e., due to a reduction in demand rather than, say, due to a reduction in the quantity demanded at prevailing prices or as a result of a supply glut, for example): access to cheap credit is decreasing, and therefore both buyers' ability to pay and demand to own land correspondingly decrease at every price along the curve.

If you like the tenant overall and just had a bad situation arise because the tenant wasn't aware maybe you agree to split the bill with them.

Electrician needs to finish his job himself so he is accountable for any electrical issues that arise.