Question #1:  only a single layer of tape is required.   you are just filling the weave with the second coat of epoxy.  in the bow and stern areas you want a second coat of epoxy to ensure that you are sealing the wood from any possible moisture intrusion as these areas are not accessable once the deck is on.  while you may not see it, a single coat is likely to leave little gaps...that can let moisture in.  a second coat is like insurance to ensure that has not occurred.

Question #2:  the deck gets attached to the hull after the epoxy has cured.  that said, there is cured as in no stickiness (typically less than 24 hours) and then there is fully cured.  understand that from not sticky to fully cured can be weeks.  i try to work with pieces like this when they are not sticky as they are a little more pliable than when fully cured.. 

that said, no real problem if you wait, just have to push and pull harder to get everything to align.  if i have a long time to wait (like i have to leave on a on holiday or business trip), i often do something with the peice to hold it securely in the shape that it needs to be.  over time, unsecured, a deck not attached to the hull will drift (as will the hull).   a simple way to do this, is to at least tape the hull and deck together (with strapping tape) until you can come back and actually seame it with epoxy.

h

   Thank You H Spira

That Is the answer I was hoping to hear, for both questions.