That herb is Thai basil, normal basil would do if you can't get that.
I use just a bit of sun flower oil to grease the wok a bit. The broth would add liquid to the thing, it'll make it juicy. Just an important thing, add the broth before the chili paste. And of course if you want it stronger, the only correct way to do it is chopping some
These noodles take 3 minutes to cook, leave them for 2 and a half, rinse them in cold water immediately so they would stop cooking and let them crisp a little in the wok. They would be your last ingredient there. Timing is not really important because of the cold water trick