This is somewhat subjective but generally I would say no.

I recently bought a duplex and was subject to the Certificate of Code Compliance.

Though I am not entirely experienced in this subject, I recall from some of the podcasts that larger banks like BoA can sometimes offer lower interest rates on their products under certain circumstances compared to a smaller bank or portfolio lender. 

@Bryan OttesonPassive income from rents does not qualify for 401k contributions, and changing that passive income to earned income subject to self-employment taxes is not generally a good formula.  

If you're getting replies and frequently then you're doing everything correctly.

But these expenses are 100% necessary compared to a lawsuit that would subject my other 10 properties from any negligence from the 1 that may have an issue.  

I just want to always be honing my method of calculating numbers because that is the hardest, most subjective and most critical part of the deal.Any advice would be appreciated.

Downpayment typically = cash or equity in the subject property.  

You can find lots of posts on the subject.

If appropriate, secure that against another property or the subject property (after close) with a second lien.