@Grant Vincent Personally, I prefer to stay at a place that's 100% wood inside, no drywall and no paint, because I want it to be as dissimilar to home as possible.

There will always be more risk with something vacant, you're probably going to be counting on one person as your "eyes" on the project (or at least for "security", overall)- and the more hands on/ closer they live / able to visit site frequently, the better. whether that is your gc, a project or property manager, or your handyman/even yard maintenance guy, neighboring teenager, or whoever- this person is key

If I made any substantial additions to it, I would be happy to share it with the community and give credit to the person who made the original.

A truck is personal property and would not become yours simply because it's on a piece of real estate that you bought. 

The wifi is what will allow you to access the door remotely.If you don't want wifi on it, Then you can still get a smart lock you'll just need to pre-program several different codes into it, and then give out those codes appropriately but you'd need to be on site at the door itself to program initially or update it.From personal experience I find the touch screen or wifi locks to be complete POS's that are not reliable and the battery does not last long.  

The person who is supposed to be in charge of our specific unit does not answer texts, and when I call it goes straight to voicemail.

Then he willfully breached the contract. 

The person you sold to would probably have a cause for legal action.However, in Austin, @T.

Quote from @Christina Swaby: Pen-and-ink changes are allowed on contracts.

You'll spend more trying to get the money than you recoup.You should not hire real estate agents to do general contracting work.