Fair point. I've tried minimalist shoes too and while they have their benefits, going completely barefoot seems like a recipe for disaster. I've seen too many sharp rocks and broken glass on trails to risk it. Plus, shoes provide some much-needed support and protection. Not worth the risk for me.
Consistency is key, I agree. I like to do hill repeats once a week, focusing on explosive power and proper form. I've found that mixing it up between short and long repeats helps prevent plateaus. Also, don't forget to warm up properly before starting your hill repeats, it makes a big difference.
I think it's a bit of both, to be honest. While pace is crucial for a 5k, you still need to be able to sustain it for 3.1 miles. I'd say focus on pace during the week with interval workouts, and then do one longer run on the weekends to build endurance. This way, you're working on both simultaneously. It's all about finding that balance.
I've had issues with gels too. Try experimenting with different brands/flavors or switching to chews/energy bars. Also, make sure to practice fueling during training to see what works for you.