Since 1031 is a federal statute it's practiced the same nationwide.   

If you haven't already you may need to simply get in contact with a good local estate attorney who knows the relevant law/statute/case to quote or the specific person to ask for in order to get them to recognize your seller as someone who can discuss the account. 

In CO it appears that PAs are not restricted in how they charge fees unless in the case of a "catastrophic disaster" per Colorado Revised Statutes § 10-2-41.3) Have a different roofing company review my roof?

I would like to find a statute that a friend can use for her tenants.

Your lease agreement will not trump the law and worse, if in violation of certain statutes, could trigger penalty provisions which would include a reasonable attorney's fee award for the tenant.You are smart to look to a realtor for a lease agreement, but it may be worth spending the extra money to have an experienced landlord attorney review and revise the lease agreement.

Look up your statutes unless someone can give you a heads up from your area

Is there a statute of limitations on collecting rent ($5k+) from a previous tenant?

You can also go to the actual statute and see what it says.

As a side note, in MO the state statute for a tenant that overstays a non-renewal, "unlawful detainer", is then required to pay double the rent for the period in which they unlawfully occupy the property.

The purchaser’s attorney also carries out searches with respect to the validity of the vendor’s title and also ensures that there are no encumbrances affecteingbthe property which may pass to the purchaser.Completion – once all formalities are completed, the purchase price is paid to the Vendor and the title deeds are handed over to and retained by the purchaser or a financial institution where the purchaser obtains financing.The above process usually takes 90 days and maybe shorter or longer depending on the complexity of the transaction.Please note that an Attorney’s fees are calculated based on a scale of fees set by statute namely the Legal Profession (Attorneys-at-Law)(Remuneration for Non-Contentious Business) Rules, 1997.