Nissan are famous for using the same look for all models variants . So a DX will have a full Ti look with the plugs just hanging off the car. They could be anything, I would not worry about them though. Yours looks like a Left hand drive model too. That first pic could be the air sensor plug for the fuel filter on a right hand drive model as that is where the fuel filter is on a right hand drive.

The one under the dash with the LED I would say is after market and could be part of an alarm or something.

Guessing on everything above but that would be my thoughts.