My pie-in-the-sky goal for this race is to bump up to s2 for the WDW M (1:53:45, ~8:40 pace).
Can you run a mile in under 7:20? That'll give you a pretty good indication of how realistic the goal is. I say that, but personally had a better race equivalency 5k, 10k, and HM time before I ran the equivalent mile time. So it's not 100% predictive, but for most is a good indicator. The matching 5k/10k times to a 1:53:45 are 24:45 and 51:22. But for someone who lacks the endurance (based on minimal training going into the last HM) the mile is going to be a good indicator of that raw speed you posses.
- When you're doing training runs at race pace, do you add a warm-up? Do you include that in your prescribed mileage?
Since the "pace" in this case is half marathon tempo, I would 100% suggest adding in a warm-up and cool-down. Something in the 10-15 min range for the WU and something in the 5-10 min range for the cool down. Something I write in my instructions:
The warm-ups are key for anything faster than "long run" pace which includes HM Tempo, Daniels T, and Tempo. Essentially, there are two main pathways for the body to use oxygen to produce energy. The aerobic pathway is mostly used in slower running. The closer you get to the point where it becomes harder to breathe (Ventilatory Threshold) the more you use the anaerobic pathway. The aerobic pathway is more efficient and faster at creating energy, whereas the body uses anaerobic when the aerobic can't keep up (because you're going too fast).
The most interesting part between the aerobic and anaerobic pathway is that even though the aerobic is used mostly during slow running it takes about 6 minutes of running before it can be used. This means for the first 6 minutes we're stuck with the slow, inefficient anaerobic pathway. So if you don't do a warm-up, and you're running faster than "long run" pace you push the anaerobic pathway too hard. This creates a deficit in energy within the first 6 minutes that becomes harder to overcome. As this deficit starts to catch up with you in later miles, it causes our running form to suffer. When we get closer to your first race we'll talk about a detailed warm-up routine done prior to the race which is extra important in races.
So for you, the EA, EB, and Long Run paces can all be started without doing any type of slow jog warm-up. I do dynamic stretching before all of my workouts and static stretching after my workouts. However, I don't like to make recommendations on stretching because the research I have read is that you're more likely to get hurt changing your stretching routine than if you did nothing/stayed the same.
It doesn't appear Higdon planned on WU/CD to be part of the total assigned mileage. So I would do the WU/CD in addition to what he assigned.
How/when do you incorporate strength training? Higdon has you take Monday and Friday off but I'm thinking of switching one of those to strength. I guess I could do T/T after the shorter runs as well, but I feel like I'm less likely to actually do it.
Higdon writes in the instructions:
"If you strength train, Tuesdays and Thursdays would be the best days to combine lifting with running. Usually it’s a good idea to run before you lift rather than the reverse."
I personally disagree with this sentiment. All advice I've read elsewhere is to put your strength training days (especially if they're leg centric) on the same day as hard runs. This keeps your easy days easy and your hard days hard, regardless of the discipline. In Higdon's advice above, he suggests doing Easy+Strength on Tues/Thurs with a hard run sandwiched on Wed. I personally see this as multiple Moderate/Hard days in a row. He would probably contest that this is doable because of the two off days on Mon/Fri.
I also agree that it would be best not to strength train on both of your off days. I personally like to see one day completely off for almost everyone (there are a few that can do 7 days per week of activities).
So looking at the plan, I would suggest strength training on Wed/Fri. I would do leg centric strength training on Fridays. Although that does depend some on how hard the karate classes are on the legs. Do you typically have residual fatigue from karate in your legs after about 24 hours? If you do, then I wouldn't do leg strength on Fridays and would instead do after the hard run on Wed. You could also consider an upper body strength routine on Saturdays in addition to the Karate class, but I wouldn't do leg centric the day before the long run.
- Should I be fueling as I get into longer runs? I've never really done that in the past but it might be good practice for the marathon. If so, any tips?
My advice is to start fueling once you pass 90 min in a training run. Any training run under 90 min, your normal eating routine should be sufficient. Once you get over 90 min, then you'll start to dip more into a place that's harder to recover from without fueling. Although it certainly can be done without.
As for a HM, fueling will play a role, but it's minor compared to several other factors (course elevation, race day temp, your training, your race pace relative to your fitness, etc.). But fueling during a HM is good practice for fueling during a marathon where it will play a more pivotal role.
Tips for fuel. Find something that you like. Lots of flavors, textures, consistencies, liquid/gel/solid, etc. So everyone is going to have a different preference. And you may find a mix of several products (not all at the same time but during the course of the run) is best for you. You don't have to choose a single product. Once you find what you like, make sure you're taking on board enough water to properly absorb the product. For most, that's going to be 2g carbs to 1 oz water. So if I eat a 25g carb gel, then I need 12.5 oz of water in and around the consumption of that gel to properly absorb it. You can't take in 12.5 oz of gatorade to absorb the 25g carb gel because 12.5 oz gatorade is already isotonic and contains carbs itself. Some products have different water absorption rates. Maurten gels are isotonic and require 0oz water to properly absorb. Maurten 320 is absorbed at 4.6g carbs per oz.
Once you find your products, and you're properly taking on board enough water, try and find your maximum tolerance level. Don't go above about 60g carbs per hour on days >90F or if the carb comes from a single source (simple vs complex). If you're taking in simple+complex, and it's under 90F, then don't go over about 90g carbs per hour. In my view, finding your maximum tolerance allows you to eliminate fueling as the reason for failure.
Also remember, any carbs consumed less than 15 min prior to the race can be considered in-race nutrition. So I personally like to drink a Maurten 320 (79g carbs) right before the race starts because I get that much further ahead.
As with everything, practice in training to find what works best for you, and then replicate that practiced method on race day.
I had been doing better with taking it easy but I think I broke it 
