If the company is hesitant, consider their financial statements to assess their stability or negotiate other security measures like a larger security deposit.

If you replace it, do not let the tenants have any say in what type or colour of carpet it is and BEFORE you get anyone in to measure or install, get it in writing that they will have the entire room emptied and make the house available at a pre-arranged time for the carpet installers.

My measurements should checks out fine (credit, Income/Debt ratio, etc.). 

It's not a perfect measure, but it's very close and year to year consistency is highly reliable due to limited new rental inventory

CPI measures general inflation for consumers for major individual expenses such as food, gas, shelter, and other basics.

If I'm in your shoes, I would keep tabs on comparable sales in my areas (I believe Zillow lets you setup alerts for sales in your target areas) and use those as your best measuring stick for figuring out your own value. 

Computers can calculate square footage, number of beds/baths, and other objective criteria, but they can't measure the subjective things like curb appeal, flow of the floorplan, view out the living room window, or the grating irritation of four barking dogs in the neighbor's back yard.Learn to study the market and how to evaluate properties on your own.

If that doesn’t work you may need stronger measures of damage and eviction.

And then meet the trucks on delivery day and take responsibility for counting, measuring, signing for the materials?

But think of it this way, if that person were to do the exact opposite of their promises/their word/or opposite of what's spelled out in your contract, what safety measures do you have to reclaim your hard-earned/hard-saved cash?