I guarantee the fire marshal would back you up.You could be nice and offer to install a $200 bike rack outside the building, but I would not compromise on storing personal items in common space. 

There's specific products for what you are trying to do.

I think you can't get this credit on an investment property but if it is your primary residence, can you apply the credit on the investment side of the duplex?

My current tax preparer does not seem to offer much of a strategy with regards to real estate and long term planning. 

I offer some of our documents in the BP File Place, available to you for free, look under Other Documents for these.As for the most recent challenge... if you have a clause in your rental agreement about unauthorized occupants, enforce it.

This type of loan product generally will not be available with a conventional local credit union. 

Side note: Anybody else get some serious "fan girl/boy" energy when people like @Dave Meyer comment on these posts.

Is it only offered in select states?

Property taxes in TX seem to be on the high side from what I've seen, but could be worse. 

It's all about supply and demand for your specific offering.