It's not that lenders do anything on their end to fix your score, but they can pull your credit report and identify the areas that are harming your score and then set up a plan to help you fix those. 

Get a hold of them and they can put you in touch with retired execs that can help you put together a plan.

Of course I plan to have the cousin apply just as any tenant would, but would you create an entirely new lease?

I am putting a 3rd floor on and already have my zoning permits and waiting on construction plans.

Check your home insurance plan to make sure it's good enough for the time when no one is there, and think about getting a property manager if you have concerns about looking after your place during your absence.

Get a first position line of credit larger than what you plan on using (Ridge Lending has the All in One that would be perfect for this strategy).

I was on the 6 month payment plan last year when it launched and was smart to do that and only lost $500.

Okay, just to counter the perspective; if you are buying as an investment did you plan to take on a job? 

Buy and hold real estate investing is a long-term plan to building wealth.

When do you plan to start a new lease?