Yes, this should have a familiar feel to anyone acquainted with the history of the Turbinia.

Since
1. They already know how to land on a barge,
2. SeaLaunch proved you can launch from a floating platform (based in Long Beach, btw),
3. you want miles of emptiness around you when launching, especially during development,
4. there was a floating rocket port in the BFR presentation,
I expect SpaceX to eventually build a launch barge that will set out from LA, go south and/or west, and launch; first to another barge, later to their facilities in FL and TX.

I believe I read somewhere that they were going to use more aerodynamic braking in the future (Block 5's only?), to use less fuel for landing. So this may have been an envelope-expansion test, basically flying sideways as much as they dared to see if it would stay controllable and hold together. They may have left the legs off and the barge in port because they thought the chances of success were low. (Spin recovery training and research has always been dangerous for planes, and in a rocket you have big tanks with liquids sloshing around.) However I would have thought that the legs would change the aerodynamics enough in that regime that the test would be more valid with them. Or, more excitingly, they could be fine-tuning their reentry models as part of BFR design work.

Methane/LOX is the propellant of choice if you want to be able to: 1. store it until later. (LH2 is a pain.) 2. produce it on Mars for a return trip. (H2O (water) + C02 atmosphere = O2 and CH4.)

One way to think about elevators and high-rises is to start from the top. The uppermost part is a little building that only needs one elevator. As you add floors on the bottom they need more shafts so that you can fill and empty the building in a reasonable time. With conventional elevators, there is only one per shaft. (Although it can be more than one floor high.) At some point the next bottom floor you add will be all elevator shafts and unless you think you can make money from a more scenic view from the top, you stop. With this tech the elevators become cars on a vertical railway and can take on passengers without blocking shafts. Big gain.

this advanced facial recognition will literally rat on you?

Because I am willing to bet there were more 3.5" floppies made than all other types of removable media put together. I have a DEC RX-02 somewhere, but haven't had to use it since 1998... ISTR they held about 500kB.

Let's assume 3.5" form factor. Using HD floppies, you need 20 million. The one on my desk is 3.25 mm thick, so they'd make a stack 65 km tall. In the spirit of Randall Munroe's What If, it would of course collapse and kill you long before it got that high.

Before this, the largest collection of collision data was the Russian dash-cam footage on YouTube

The original Green Hornet had a spy drone that launched out of the trunk.

Sounds like a cage fight to me...

Actually, some mountains (notably Everest) and the deep sea trenches are there because of plate tectonics, not despite it.

Grabbing it would almost certainly crumple the tank. It is not designed to take much in the way of sideways loads.You would have to add a flange or some hooks to the top of the first stage, and thicken the skin, which would add significant weight (although getting rid of the legs would help). The elegant thing about a pad landing is that it is just like a launch in reverse - all the loads are in the same direction. It's just that the mass is way less and the CG is much farther down.