Just wondering if you figured out the operation of this cap.  My 2001 215 Sport has a similar one and I'm thinking its not working or maybe I'm overtightening it.  On a day in the the 80s (or warmer) my carbs will weap fuel and drip om the ground.

For the hull sides, if you're next to the transom where the new glass will overlap from transom to sides as Rick described just be sure it's ground clean and free of things sticking up that would cause an air void in the new glass. But you don't need to grind the weave of the heavy woven glass out.
grind the ridges flat - do you mean at the ends of the new glass? If so, and you plan on overlapping with glass later on, then yes you'll want to knock that ridge down to once again keep from getting an air void under the new glass.
Best to layup the new glass wet on wet if you can stand the work hours, that would avoid having to grind between layers.

oops
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Thank you gentlemen. On the hull sides on the heavy biaxial I assume it needs to be ground flat in relation to the significant relief/texture of the material itself.... grind the ridges flat? For that matter, how long does a grind last assuming it gets nothing like grease or dirt on it?  Ya'll, for the record,  are ridiculously helpful and gracious with your time and knowledge.  Thank you.

Usually when you redo the transom coring, you plan to lay in a couple of layers of 1708 to beef up the transom skin. Laying in the 1708 usually includes grinding the inside transom skin and about a foot of the inside hullsides and inside bottom. You can fill in the voids with layers of 3/4oz CSM (chopped fibers) and then cover with the layers of 1708. Lamming the 1708 to include the hullsides and the bottom creates a complete tie-in and makes the transom really strong. Then you start adding the coring, using fillets of thickened resin at all the corners, to include where the transom meets the hull bottom. You seem to have cut the stringers back enough to allow for this.
If you need more info let me know.  There are a lot of examples of doing this.