I am no expert but have rebuildt my far share of rods over the last couple of years.

1. I prtty sure you are going to hav to ream the EVA foam.

2. To me winding checks are just mainly for looks thy don't have a hold ot of strech to them.

3. No but you might have to build a arbor for the foam beacuse the butt section is going to be larger than the blank by your real seat.

4. no but a dremel with a cut off wheel will give you a smoother cut.