Training For A Gran Fondo: Nutrition Cat 4 Questions. Mmmm, Carbs. Protein.

I am training for a 80 Mile Gran Fondo this summer and would like some feedback/recommendations/tips on Diets to follow. I bike 3/4 times a week, and play ice hockey twice.

My three main questions are:

1. I am looking to stick to about 50% Carbs, 30% Protein and 20% Fat. I feel that if I don’t get enough Carbs I feel sluggish (from a previous breakdown of 40%, 30%, 30%). Does this mean that my body might become more used to using Carbs as opposed to Fats to fuel my ride? Would I want to use Fat more?
2. I’ve read about getting a post-ride meal, at 1g per 1kg of carbs, and 10-20 g of protein withing 20-30 minutes of riding. I imagine though that this isn’t always the case, for example between a 1 hr ride and a 1.5 hr training session. How are the quantities written above changed depending on intensity? For example, an all out ride --> 1 g for 1 kg, and a 7/10 effort ride might be 2 g for every 3 kg?
3. I haven’t ridden more than 1.5 hours at a time, but at what time should I start eating? After 1.5, 2 hours, or even as early as within the first 30 minutes. I would just like to begin training that portion as well, with reaching back ni the jersey pockets, seeing what suits my gut, etc.