All your points are sound. The issue that I have with this is that remote disable functionality is not necessary to achieve any of these aims. Before they were connected to the internet, people were still able to rent/lease autos and the world managed to survive just fine. There were other ways for lenders to get remunerated for breaking lease terms - they could issue an additional charge, get a court order for repossession, etc. Remote disable was never needed or warranted.
So let's start by considering the due process here. Before, there was some sort of process involved in the repossession act. With remote disable however, the lender can act as judge, jury and executioner so to speak - that party can unilaterally disable the device with no oversight. And if the lender is in the wrong, there is likely no recourse. Another potential issue here is that the lender can change the terms at any time - it can arbitrarily decide that it doesn't like what you're doing with the device, decide you're in breach, and hit that remote kill switch. A lot of these things could technically happen before too, but the barriers have been dramatically lowered now.
On top of this, there are great privacy concerns as well. What kinds of additional information does the lender have? What right do they have to things like our location, our habits, when we use it, and all of the other personal details that they can infer from programs like this?
There are probably lots of other issues here, but another part of the problem is that we can't even start to imagine what kinds of nefarious behaviors they can execute with this new information and power. We are well into the age where our devices are becoming our enemies instead of our advocates. I shudder to think what the world would look like 20 years from now if this kind of behavior isn't stopped.