Yes and yes
There is the road that you can drive on and park at one of the many lots (free). I would recommend parking up top and walking the rest. It's a nice walk and you can take plenty of pictures.
Yes, just make sure to use the crosswalk when walking across the road that crosses the dam.
Yes. When you come out of the tour, you're right there on top. You don't have to take the tour, but it was totally worth it.
Yes and yes. Would also walk across the bypass bridge. There's several steps but if you're able, it's worth it.
Yes on both sides
Yes
Yes/Yes, lot 13 is a good location, don't panic if you don't find a parking spot within the first few lots as you come in. And by no means is it necessary to park in the multi level lot.
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