Most of these fence panels are bi-facial, i.e they have panels on both sides. They catch light reflected from the ground/snow/etc. They cost a bit more than single pane panels, but not a lot more. Like 15-20%.

You dont get nearly double the power, but they tend to work a bit better then single panels facing the sun because solar panel efficeny degrades with heat. When the sun is at its strongest, traditional roof mount panels take a significant efficiency hit. Because bifacial panels are generally positioned more flexibly, they have much better cooling that compensates for their bad angle.

Have no idea what you mean about vandalism. I see solar panels all around in various neighborhoods in a big city and they are never damaged. You will likely never have an issue, and even then the individual panels aren’t that expensive to replace. A wood fence would likely cost more to cover the same surface area of one 7ft x4 ft panel.