I think it's dangerous. Starboard and similar cautions against using 5200/4200 as a glue. It might work for a while, then suddenly when going 40mph the assembly comes unglued and from the pressure of the water swings into the cockpit, smashing into the deck.
Hopefully nobody will be hit. Those little stick on cable tie points aren't going to help much.
Besides, once you get the trim tabs on that boat, a few extra screws won't hurt a bit.
