I don't necessarily mean sending animals. I just wasn't ruling it out either. Maybe just an empty Dragon V2, or maybe with added sensors, possibly something to simulate human weight, heat production and respiration.
As for bathroom needs, think they will have a space toilet like on the ISS? Kind of strange to think of a toilet in Dragon V2, but would probably preferable to other options, especially for commercial customers.
Sending 2 people up in a Dragon V2 capable of handling 7 people means there will be no shortage of life support capability.
SpaceX will first do the unmanned orbital Dragon V2 mission before this around the moon mission.
We're in 2017. We can simulate almost everything that happens inside Dragon to very high detail.
Some things can be tested in the real world without risking sending people to orbit.
Want to test life support ? Put Dragon V2 with enough people inside a vacuum simulator and let it do its thing for the whole mission duration.
Want to test its course corrections capabilities ? That will be tested on the unmanned Dragon V2 test flight (which is scheduled to take place late 2017).
SpaceX knows their stuff.
Assuming the unmanned Dragon V2 flight takes place without issue, I'm left with two concerns about this around the moon flight... Any Falcon 9/FH unknown issue. SpaceX intends to do about another 20 F9 launches and maybe 3 FH launches until then. That certainly helps. And the re-entry profile (much faster than LEO orbital velocities), but the re-entry is much easier to simulate, and Dragon V2 reportedly can handle return even from Mars (which is even hotter/faster than from the Moon).
Lets be rational. If you're not an engineer/scientist, let the pros do their job.
It took NASA dozens of flights from the first John Glenn suborbital flight all the way to the moon landing cause the biggest computer they had back in the late 60s/early 70s was less capable than a basic android cell phone is today.
Take for instance the new SpaceX Raptor engine. The full engine is already on the test stand. They got through the whole component testing without a single explosion and the engine has been test fired a few times, without blowing to bits and pieces. This is mostly due to ultra advanced computer simulations done throughout engine design cycles.
Its too easy to do monday morning quarterbacking... Trusting the engineering is hard.
Lets remember that:
the CRS mission failure was the result of 3rd party faulty components. Not a design problem.
the AMOS static fire explosion was a consequence of SpaceX pushing the boundary of space flight. The sort of problem nobody even considered cause nobody was using deep cryo LOX/Helium.
At the same time, the Dragon capsule family has a pretty good history. Except for a few in flight hickups which were all dealt with backups, resets or software corrections uploaded within hours, Dragon has delivered every time.
Wanting SpaceX to send an empty Dragon V2 in the same mission profile is the opinion of those that don't respect the very hard work SpaceX has done. And little respect for aerospace engineering in general. Even sending a dummy mission ahead of time can't retire 100% of risks. Space includes loss of life risks. Those that signed up obviously understand that.