Passenger Seatbelt anchor and key fob operation

Long title I know, just have a couple quick questions that have popped up in the past couple days. Is there a specific reason why the passenger seatbelt is mounted to the side of the seat as opposed to the floor such as the drivers side? My only guess is for a child seat.

Also wanted to know if the key fob will work once the key is in the ignition and fired up. I tried to work it but it seemed to have disarmed itself. I figured it would be good to have it on a seperable key chain so I could keep the car running and still lock the doors if I needed to run in the house quickly. Is this the dummy feature that doesn't allow you to lock your key in the car while the car is still running?

Oh yeah one other question I forgot to throw in. I ran my tank down quite low tonight, I believe there was about 8 litres left, anyways the display usually shows how much further I can go before I run out of gas, I ended up with ----- on that screen, what happened? I know it isn't really that accurate anyways but I was curious as to why it did not show anything, I have seen it go as low as 50 km left.

Oh yeah one other question I forgot to throw in. I ran my tank down quite low tonight, I believe there was about 8 litres left, anyways the display usually shows how much further I can go before I run out of gas, I ended up with ----- on that screen, what happened? I know it isn't really that accurate anyways but I was curious as to why it did not show anything, I have seen it go as low as 50 km left.

Once it figures you're below 30km it will switch to that, and I've never seen it go back up at that point.

Andy