I'm assuming this is a long term buy/hold since you don't mention disposition.  

I am a diligent startup entrepreneur striving to yield positive results and success in all ramifications through professional disposition and indulgence in all necessary skills needed for making sound business decisions that will impact my investment ventures

To that extent, do not look to completely invalidate the mortgage claim but rather bring it to more of a fair disposition.  

My contact info was included in a disposition letter that was sent to them stating they owed thousands of dollars due to unpaid rent and damaged sustained to the property.I am concerned they might retaliate because these tenants were recently evicted from my property.

Additionaly, there is some caulking that should be done in the apartment anyway, so I want to try to seal it up better regardless.I'm hesitant to bring in a professional at this point, but I'm not sure if my pre-disposition against that idea is correct or not.

I am interested in following discussion threads re matters involving disposition of rental and investment properties pursuant to divorce.Because of the possibility of beneficial section 1031 tax treatment, I wish to follow discussions about conversion of residential primary homeowner property in part or full to rental property and tax treatment upon sale after 2 years or longer.I frequently am asked to provide consultations on these subjects when involved with divorce financial analysis.

Here are exemptions to Due on Sale(d) Exemption of specified transfers or dispositions With respect to a real property loan secured by a lien on residential real property containing less than five dwelling units, including a lien on the stock allocated to a dwelling unit in a cooperative housing corporation, or on a residential manufactured home, a lender may not exercise its option pursuant to a due-on-sale clause upon— (1) the creation of a lien or other encumbrance subordinate to the lender’s security instrument which does not relate to a transfer of rights of occupancy in the property; (2) the creation of a purchase money security interest for household appliances; (3) a transfer by devise, descent, or operation of law on the death of a joint tenant or tenant by the entirety; (4) the granting of a leasehold interest of three years or less not containing an option to purchase; (5) a transfer to a relative resulting from the death of a borrower; (6) a transfer where the spouse or children of the borrower become an owner of the property; (7) a transfer resulting from a decree of a dissolution of marriage, legal separation agreement, or from an incidental property settlement agreement, by which the spouse of the borrower becomes an owner of the property; (8) a transfer into an inter vivos trust in which the borrower is and remains a beneficiary and which does not relate to a transfer of rights of occupancy in the property; or (9) any other transfer or disposition described in regulations prescribed by the Federal Home Loan Bank Board.

However, I am not a junior lienholder, I am the property owner by way of the junior lienholder's disposition of the property.Any thoughts?

Here's a few lines from a local bank's recent SEC filings regarding notes: "During the third quarter of 2014, the Company identified problem assets and began the disposition process under the asset resolution plan... the Company transferred $11.2 million of loans held for investment to loans held for sale in anticipation of near term loan sale..."

I can't say whether they will require you to use their broker, but since they are typically not handling the properties under the same type of disposition plan that a bank would handle an REO, you've got a shot!