Last year for hydration I had my aero drink filled with a mix of 1/2 H2o, 1/2 Gatorade. A second 20 oz. bottle of all Gatorade and a third bottle on my seat rack of just frozen water to squirt off/drink if needed.
I also had in my binto box/taped to my top tube:
2 Hammer bars, choc peanut butter.
and 3 Power Gels.
I took one bottle of Gatorade at the second water station, skipping the first and 3rd as I still had a good supply on-board.
During the ride I drank at will making sure to drink at least the aero bottle and one of the 20 oz. bottles of 50/50 mix.
I also ate one gel within the first 15mins on the bike, then alternated between one bar at the hr mark, then a one gel 45 mins later, then a bar 45mins after that, then a gel 45mins later etc, during the ride.
I believe I went thru a total of 2 gels and 1.5 bars, plus 2.5 bottle of gatorade/water mix during the ride.
In T2 I had a bottle of Ensure I stached in my running shoe and 2 advil.
Then on the run I drank .5 cup of gatorade and a few sips of water at every other water station. I also put ice in my running cap to keep me cooled off.
I took Power Gels as needed about every 45mins during the run.
But remember, EVERYONE is different and you should be testing your OWN hydration/fuel needs NOW in training to see what works for you.
Most of your other question are answered in the Athlete Guide.
FM