I think it all depends on what you are looking to do with the social media / how you want it to help you.

Now, some of these answers will depend on what state that property is in, how much equity you have, and a couple of other factors...but you can certainly seek out other lenders about a Line of Credit on an investment property.  

They have every incentive to make sure construction is up to standard since they will receive 5-6% (to be split with buyer's agent depending on state) of the sale price in commission.

Because of all of this depending on your investment goals, one may make more sense than the other. 

Meaning the at the end of the lease, the tenant has the option to buy (but not the obligation) whereas the seller has the obligation to sell if the the buyer chooses to buy (works just like selling stock options!)

My initial instinct is to wait for the results of these two efforts, as your asset protection efforts seem to depend on them.

You may have to do month-to-month leases.Regarding the basement, most cities really don't care if the homeowner chooses to live in the basement.

Discount depends on model but the discount is about 50% off of retail,  and arrives within a week direct from manufacturer. 

It depends upon what your current rate is, how much equity you have in the property, does your current financing have a prepay, and what your plan is for deploying any cash out.

It depends on the guy you get, but typically not a big deal.