Intention to rent Investment Property. Second Home loan status?

[Stan C.]

I want to apply for a conventional loan on a duplex out of state. Both units are currently rented and I intend to keep renting them. A mortgage broker said one of his underwriters may approve a loan as "second home" with 10% down (versus traditional 20% for an investment property loans). Is that a violation of any laws/codes to have a "second home" loan on a property that is actually an investment property?  What are the chances of running into troubles down the road? What are the downsides of doing so?   Can tax deductions be exactly same for both scenarios?  

I won't be under an LLC. Insurance would be for "investment property". It would be managed by a PM company.