Personally, when I'm walking thru a parking lot I'm watching all the cars tail lights. If I see red ones, or if I see car exhaust I know to watch for that car to start moving, when my girls are with me I tell them to "watch that red car" (or blue, green, whatever will help them ID it quickly). It's not just the driver's job to watch for people walking, it's also the responsibility of the person/people walking to watch for cars in the parking lot.
when I pull thru I do it slowly, to make sure no one is coming from the other side. But I rarely pull thru as I'm normally shopping so need the access to the lift gate in back (again I drive a minivan). Unless I'm just grabbing milk, then I can just open the sliding doors on the side to put the milk in.

that person was in the wrong, she should have yielded to you as soon as she saw you, what she was doing was not smart.....also note, that I do not pull thru like the person described in the above quote...I would have pulled into the spot in front of you and then thru to the other side, I would not have whipped around from the other lane to try to take the spot, especially if someone was behind me......
It's not illegal to back out of driveways here, not at all. I lived on a main street, it was residential but very busy and I backed out all the time. Where I am now is a very small street (like 20 houses for the whole street), it's not usually an issue.
What do you mean backing from a minor road to a major one tho? that last line is confusing me a bit.

I don't back down streets.....just from parking spots or out of my driveway generally.