I like the idea. I do believe you're putting a bit too much description into the stand box. I think just saying "Can turn any object or surface into a bouncy surface"
And when you say "effects only the user and not others" do you mean it can only use it on non-living things?
I would also work on stats a bit. For a stand you say is slow, a B in speed may be too fast. I personally judge them by base ability without powers added in.