Absolutely - and that's what I was trying to promote when commenting on the longer over water flights suggested by tb10er (for example).
I'm pleased to read that somebody is thinking through the flight beforehand and considering the worst case scenarios.....and it's exactly what bugs me when, as a flight examiner, we are expected to give a PPL candidate just 45 minutes to plan an entire, albeit somewhat easier, trip.
I think you are approaching this in exactly the right way for your experience level - it's not they way I would do it personally, but I'm probably a bit further down the food chain than you are right now.
Keep it up - let us all know how it went. Whilst I agree with 99% of your planning ideas, my first suggestion is......RELAX!!. You'll enjoy the trip much better.