you could, but you would need to provide some form of traction on it. When I first tried wakeskating, i just used my first wakeboard (which was what everyone did, since at the time wakeskate specific boards didn't exist). I didn't wax it or have pads, so the fun was limited to lipslides and riding the nose.
fins and no fins is a preference thing. I love fins, so i ride with them on.
Truthfully though, unless you're going to mod this board into a make shift wakeskate...I dont think you'll really get the full effect. To have a proper board, like a flat deck at the very least, would be nice in that you'll have a better feel for what you're dealing with, like ollieing, shuving and whatever else.