Starting with cold water is the correct traditional Italian way, since 1933; and it doesn't burn the coffee because they turn off the stove early, as soon as they hear the Moka pot start to gurgle. The coffee will finish brewing off the stove due to the heat inside the pot. For a traditional tutorial, search for the "Annalisa J Moka pot" video. The Moka pot videos by "Il Barista Italiano" and "Italian with Bri" show when to remove the Moka from the heat.
You don't need to weigh the coffee. Bialetti said they designed the Moka pot to be a measuring cup, so you get the right ratio of coffee to water when you fill the water to touch the bottom of the pressure valve and you fill the coffee basket loosely until the coffee is even with the rim, but don't press it down.