Installing New Deck ? Bolt,screw or clip? Seal Marine Flooring? Vinyl Glue?

[BeachBum57701]

I am redoing a 1970 Kayot pontoon and it is time for the deck to go on to the alum frame. Orginally it was only bolted around the outside edges of deck to the frame. Between the four foot sheets of plywood there were these JH clips. I am not sure what to call them. The wood slide into both ends of the H and the J hooked around the frame. Now that I am redoing the boat which is the best way to go? I see the nice 1" head deck bolt kits or just the self tap deck screws? I would think the orginal way was not very sturdy but maybe it needed the flex???
Also, i picked up the marine grade plywood. Do I need to seal this? Is there anything local I can pick up?
What does everyone suggest for gluing down the vinyl flooring. On cabela's site (where I got the flooring) everyone states the carpet/vinyl glue was still wet after a week when they tried it on vinyl?