Karl, Most of my experience with heart rate comes from standard endurance training, I generally do not use it for strength training because it's not as relevant. Kettlebell ballistics however can be a sort of hybrid area. As for your example, you are spot on about the power production in 2A vs 1A swings. As Pavel has talked about before you get more power production from 2A swings. Since your body is producing more power your heart needs to pump more blood.
A more drastic example of this comes from contrasting the strict press with the jerk. Now, strict pressing a kettlebell is much more difficult than jerking a same size bell. However, since the jerk requires a strong leg drive, a ballistic thrust, and a second dip it requires a lot more energy, so heart rate will be higher even though you may be able to get many more reps with the same weight.
Jeffrey, that does count for something, and is why for individuals I much prefer HRR over Maffetone (though for many younger people like myself it ends up being pretty much the same). Max heart rate and resting heart rate are very relevant for determining zones.
Resting heart rate should be taken lying in bed first thing in the morning. You can either keep your heart rate monitor next to your bed, or just use a stopwatch. I recommend measuring for a full minute to get a more precise reading.
A step up from measuring resting heart rate is measuring heart rate variability, which helps to determine your parasypathetic/sympathetic balance. It's a topic that has a whole lot written on it, and I would not do justice by trying to summarize.
A couple pages ago there was talk about heart rate during get ups. Get ups are an incredibly hard to classify exercise for a number of reasons, but chief among them is the fact that it's a dynamic-static movement. This makes heart rate very hard to reliably gauge. During static efforts heart rate and blood pressure take a large spike. This is because muscle lengths do not change during static exercises, so there is a prolonged contraction. This prolonged contraction doesn't allow for blood to flow into the working muscle which causes an increase in metabolic byproducts.
A few more thoughts. Exercising the glycolytic pathways is not inherently bad. What is bad when you are constantly using that pathway and putting your body into a constant fight or flight mode. Most people need more aerobic improvements than anaerobic, but once you begin improving your cardiovascular system working in some higher intensities can be of great benefit.
Higher intensity anaerobic work has a number of benefits, it helps improve power output, causes muscle damage, and elevates testosterone/growth hormones. But it needs to be done smartly and sparingly.
This is where something like an easy, medium, and hard system works very nicely. Here is an example of how I might apply that to 10x10 swings using HRR.
First step: figure out zones for heart rate reserve. A couple years back I did a series of vo2max tests in a laboratory, and the max heart rate I achieved on those was 196, so we will use that as my max. My resting heart rate has averaged at about 54 so that will be my resting rate. Plug it all in to get HRR= 70%(196-54)+54= 153.4. So, that will be my aerobic cap.
Less math version: http://www.digifit.com/heartratezones/training-zones.asp
On easy days I will use a cap of 153, and allow full recovery (I like to use twice resting heart rate, so in this example it would be 108. If halfway through the workout I find that I'm getting too close to the cap or going over then it's time to drop down in weight or in reps.
Medium days: Still keeping a cap of 70%HRR (153 bpm), but not allowing for complete recovery. In this case beginning each interval when my heart rate has dropped to 50%HRR (124 bpm). The same amount of work will be accomplished, but the average heart rate will be higher and the work will be done in less time (higher workout density).
Hard days: on these days there will be no heart rate cap. Weight or reps may be increased to increase the level of exertion. However, we still want to recover between efforts so sets will only be started when heart rate has fallen below 50%HRR (124 bpm).
Now, if you really wanted to focus on endurance training the protocol could be adjusted for that. You would do the same thing as the easy day, but you would not stick to 10 reps or 10 sets. Simply set a timer and go. Swing until your heart rate begins to approach the cap, and then rest until your heart rate hits the minimum. As you fatigue the reps would slowly decrease, and the rest between rounds would increase. At the end of however long you went (say 30 minutes) you would record however many total reps you got. The goal would to over time increase the density of your workout, and then eventually the length.
Just a quick overview of a possible way to organize training using swings and HRR zones. It's a very brief description, so let me know if you have any questions.