“When making pie crust, rubbing the butter into the flour or using a fork/knife/pasty blender to achieve “pea-sized” crumbles.
Pretty much every recipe will describe it this way, but the expanding water from the butter drives that beautiful flakiness. Use a cheese grater with moderately large holes. Use very cold butter, and handle the butter lightly so that it doesn’t melt into your hands. Grate it and toss it into the flour about 1/3 of the butter at a time, tossing it to coat it with flour. Then make your dough. It will be light and flaky and heading in the direction of puff pastry.”
....So where exactly do you think those minerals in your water heater came from?
The water heater isn't generating new filth, if anything it is filtering it out.
If you aren't getting crystal clear hot water, than you need to have your unit cleaned or replaced.
Quote from the U.S. EPA: USE ONLY COLD WATER FOR COOKING AND DRINKING. Do not cook with, or drink water from the hot water tap. Hot water can dissolve more lead more quickly than cold water.
The same EPA that tells us everyone is going to die if the temperature goes up 2 degrees?
#6 I use my flower coated hands to mix the butter in then put in the freezer for 30 minutes
#8 If it boils over you need more a larger pot and more water for that ammount of pasta. And mind your temperature, you don't need a rolling boil. Add the pasta to a rolling boil and slowly turn the heat down remembering that adding food to a pan will cool it down initially.