On the outside of the hulls you will see two plugs the cover bolt holes; the same bolt holes exist on the inside of the hull and this is where you mount the plates for the cleats. If you have tramp tracks then you will find two 1/4-20 bolts already in the holes. Remove the bolts and loosen a few screws on either side of the mounting holes so you can slip the cleat plate behind the track. Be careful not to entirely remove the track screws as they can be a pain to reinstall. If i recall correctly the screws are several inches long.
The plate faced toward the center of the boat over the tramp.
I dont tie the halyard ends together, but its a good idea to secure them to the cleat so they dont get blown out of arms reach when you step the mast.
Jib sheet loop: Sure, you can tie the center of the sheet to the clew on the jib, but be sure to put a stopper knot in the end of the rope or you will loose it through the cleat when you tack and release the sheet. You may also be chasing the jib ends all over the tramp if you dont run it in a loop. I changed to a 2:1 jib sheet set up, so it's always mounted on my boat and runs in a loop.
I also added 3 extra hanks to the jib. This will help the sail keep its shape and in my opinion is 100% necessary.