A slow plane no problem but as you go faster and move towards the back of the board the tail rocker will cause the nose to rear up in the air like in the video, this is pretty ungainly and unmanageable IMO.
I think that fin will be ok in that finbox, it's not that huge and they made the fin that big for that box, at a certain point they don't get any longer for a US box for obvious reasons.
Can't wait to hear how it goes

Those side bite fins probably have angle inward, you should sail it for a bit then take them out, I'd be curious.