very common strategy for high net worth investors..  

Expecting to get a quote that you are looking for by just showing the pictures to the contractor is not going to work .Even if someone agrees once they start work they will bring up or scare you with other things inside the house and the common excuse will be that they never saw the house.

Also, the project could actually take longer than the 1st house if the contractor adds contingency days to the schedule to mitigate the risk of damages  Good luckAs far as the payments go, there are 2 standard billing practices, percentage of completion which is by far the most common or you include drawers in the construction schedule based on completion on milestones.

I believe most (I do not really know the stats, but fixed rate is an common option) refinances are fixed rate.We use HELOC for shorter debt such as to purchase a property that we plan to value add and refinance in the near future. 

Or do you get a mortgage that is split up as a tenancy in common or joint tenancy?

In my state, this is the most common way to transfer ownership.

In Worcester they have what is called ZERO LOT LINE where you can share common walls with someone but everyone is responsible for their own exterior maintenance and roofs. 

I think the common denominator is that I need to network a little better at these meetings.

A common misconception is that agents are solely responsible for finding deals; that they’ll be out there all day beating the bushes for just you and magically making off-market deals appear that meet all your criteria.

From the details you provided it like you are on a net lease, which is common in the commercial space.