I'm trying to work out why, exactly, they are a problem when you are backing out. It looks like a straight driveway? But oy, that green box. I'm not sure what it is (I live very elsewhere) but it looks as though it would be illegal to box it in with a better-looking box. I'd put triumphantly colourful shrubs around it. Oleanders? On your side, of course. You might have to see it from the street, but why should you have to see it from your house?

I would keep the walls and columns but remove the ones that are immediately next to the driveway. Then regrade that area and plant plants in the area instead of grass

Check to see what the easement for the green box says about what you can and can't do. The "call before you dig" helpline sends people out to mark underground utilities- in my area it's very quick.