Getting the large holes is largely a function of how you treat the dough before cooking it. It is vital to have properly developed gluten, first of all, and you know all about that.
Second, you need to have a dough that encourages gluten networks to be longer instead of tighter. This is why you always need to relax your dough for 20 minutes before you bake it. If you were to throw it in the oven just after kneading, then the dough would hold on to its shape as tightly as it could during the crucial oven spring phase, where the dough has its best chance of rising before the heat solidifies the gluten network. The oven spring happens because the air that’s already in the dough gets warmer, and so expands, and also somewhat because the yeast get a little more life due to the heat before they’re thoroughly cooked, and so they are extra active until they die.
Third, you need to have enough food for the yeast to feed on while its doing its extra rising and oven spring. Traditionally, this comes from the starch in the dough breaking down over time, which is one of the reasons why dough that goes for a long rise works really well. Enzymes in the flour break it down into food for the yeast as well as new flavors for the dough, so it’s very handy. Another option is to add a little malt syrup or sugar to the dough, which is easily digested by the yeast and doesn’t tie up the water in the recipe like sugar would. Only do the malt syrup if you aren’t going to do a slow rise.
Fourth, you have to keep the yeast distributed. When yeast multiply, they do it in tight groups, like grapes, so they rarely get a chance to spread out throughout the dough on their own, especially if it’s a relatively dry dough. This is why you “punch down” the dough. I put that in quotes because you don’t punch down the dough, despite what people on TV might say, but instead you fold it over. The idea is to cause as little damage as you can to the gluten networks while spreading out the yeast that have grown since the rise began. If you get too many yeast in one area, not only is there not enough food for them all, but the alcohol that they produce will, in a high enough concentration, kill them off.
Fifth, be careful when putting the dough into the oven. You want to ensure that all of the bubbles that have developed so far are preserved, so don’t jostle the dough too much when it goes in. Just place it carefully.
Sixth, you need a damp oven environment at the start of baking. Having a humid oven will keep the outside of the crust from setting too quickly, allowing the oven spring to be more impressive. If the oven environment is dry, the water on the outside of the loaf evaporates too quickly, and the loaf sets before it can expand very much. You can accomplish this by way of a spray bottle to squirt the inside of the oven (being careful not to let water touch the glass on the oven door or around the light bulb), or you can heat some rocks at the bottom of your oven in a pie dish and pour water into that, or you could buy a fancy steam-injection ovens. I want the steam-injection oven, personally.
Seventh, use a lean dough. Regular sugar and honey ties up water, which reduces gluten formation. Fats coat flour, which reduces gluten formation. This is why a white bread has a relatively tight crumb, while a baguette has a wide and airy crumb. This also helps on the crust formation for the same reasons.
Another thing necessary for crust formation is a hearth-style oven. You have to put a lot of heat into the bread pretty quickly without letting the temperature drop. There are many ways of doing this, from adding baking stones or tiles into the oven to building a brick oven. Your normal oven has metal walls that only store a bit of heat, so opening the oven door lets a lot of that heat out. With a hearth style oven setup, you have stone or clay that absorbs a huge amount of heat, so when you open the door and let all the heat out, the heat from the stones quickly replaces the lost heat. That heats up the outside of the loaf well enough to form a thick and crunchy crust.
Using all of these tricks, you should be able to make whatever kind of crusty, delicately-crumbed loaf you want. The most important thing will be practice, though. Mastering that style of bread is a tricky proposition, and will definitely take some work to be really good at it.