Re-Carpeting Tracker Deep V

[Handyman663]

I am removing the plywood decking and had 2 questions:

1) When I reinstall the decking I want put the screws thru the carpet. I cannot imagine any way to exactly hit the old holes with the new carpet covering them. Should I just put the screws in slightly different locations or am I missing some neat trick?

2) In a previous thread on this subject jigngrub used what he called an epoxy resin to coat the plywood. What would a trade name be on an appropriate product?

Thanks for any help.