For the past 3 months or so, I've been trying to track macros while keeping an eye on calories. On lift days, I've tried to go over by 300 calories or so, and on rest days I've tried to be at or under the calories for the day. Mostly, I log only during the week because I can't/don't make time to log foods on the weekend.

That WAS my approach. It resulted in weight gain, not all of it muscle. My new approach will be to let my body be my guide. I do try to log everything early in the day so that I can plan accordingly; for instance, I know I'm eating a big dinner tonight and having a PWO shake, so I may ease up at lunch. But I'm no longer attempting to stick to macros or calories. I want to be in the ballpark, but I'm not trying to program out every last nibble. There will be days that I'll undereat protein or carbs, and that's OK because on Fridays I know I'm going way over. I'm not going to be calorie cycling anymore, although I will probably do carb cycling intuitively.

Things I learned from my previous approach:
1) I can't carb load with sweet things, except MAYBE some dates at the end of the night.
2) I may be a poor estimator of how much food I have on my plate, depending on the meal.
3) Rice is awesome, but in the short term I'm going to have to cut back on my portions.
4) Alcohol has carbs, but they aren't the good kind that you want for recovery. And they're a double whammy if you're eating something sweet, since the body will immediately store that sugar as fat in order to process the alcohol first.
5) Creating a weekly caloric deficit makes more sense for me than a daily deficit, given my Friday night beer and pizza. It's worked for me before, it's what I'll be doing again.

I think today is going to be a fairly representative day for me for a while. High protein (1g/lb BW), low-ish fat (.5g/lb) and low(er) carbs (~.6g). Carbs generally timed to be post-workout (HIIT at lunch today). Calories are well under for the day, not by design but by circumstance. I don't anticipate being hungry this evening given what I've eaten today, but if I end up getting hungry I'll snack on some clean carbs this evening.

Planned carb refeed on Friday night. I'm not lifting this week because it's my deload week and I'm focusing on experimenting with some HIIT ideas. When I hit the weights again, I may end up hungrier in the evenings and load carbs more.

Improving to just over a 6mph pace in a couple months definitely seems achievable. One method I read about to improve your time for a distance: run faster for shorter intervals. So if you want to improve your time on 1.5 miles, for instance, run some 200m-400m sprints, or work on running 1K as fast as you can. You sort of train your body to run faster than it thinks it can.

It definitely helped me. I haven't run in a while, so I'm sure my pace has fallen off, but I was able to improve my distance speed to the point that I could run 2.3 miles in about 19 minutes this summer.