I assume CSA is the same as CN so I'll try and answer your questions. The resort course divers and even the certification course divers do not dive with the certified divers. They dive between our dives (9am & 1:30pm). Resort course includes one dive and I believe additional dives are $50 each.
Certification is only 2 days total so it is doable if you are there for 5 days. Remember he can't dive 18-24 hrs before flying.
Couples Negril - September 2011, 2012, 2013 and have just booked 2014
Scuba Club Cozumel - Jan, Apr & Nov 2012 and Jan & Nov 2013
Cobalt Coast, Grand Cayman - May 2013
Retiring & moving to Cozumel, Mexico in early 2014