We're millennials and we like to travel way too much to be living on beans and rice. 

If you haven't already done so, check out some of the beginner guides and other helpful "stickies" on BP.http://www.biggerpockets.com/real-estate-investing

From what I've read a contract has to have certain language for a lien to stick. I

I can see this getting a little icky sticky down the road when we go to sell inasmuch as we would all be factoring in his improvement costs when splitting up the loot from the sale.

I'm going to change my contracts with her to state that she will receive 120% of the first month's rent if she has the property rent-ready and inspected 4 weeks following vacancy, 100% if it's 8 weeks, 75% if it's 12---etc... that way I'm leading her with a carrot on the stick, rather than just a typical stick. I

Abraham Bakre,I suggest that you spend some time in the following forum:Landlord and Rental Programs.Here is the link: https://www.biggerpockets.com/forums/52-rental-property-questions-landlording-issuesIn that forum, I suggest that you spend some time reading the first four "stickies."

And you're going to have small items and vacancies all the time.Read the sticky threads in the rental property forum.

at my college 2 or 3 years ago, living on campus was 3 or 4 grand a semester, and they had a mandatory meal plan for on campus students...basically around 15 grand a year was thrown away on crappy food that we hated eating (but did cuz we had to pay for it) and rent on a crappy dorm..that is how i bought my first house...it was cheaper to pay a mortgage and cook rice flavored with BBQ sauce!!

If you deviate from the written word you'll potentially find yourself in sticky situations later. 

If you put a fridge and maybe some type of hotplate, microwave, toaster oven, slow cooker, rice cooker, electric kettle.