Our home has gray plastic water lines. Someone said these lines are likely going to leak. Our home is 30 years old, don’t you think if the lines were going to leak they would have already?

The lines you are talking about are likely poly “B” lines. While it is true these lines have had a poor history and many homes have flooded from this type of pipe, you need to consider a couple of things before you get too excited. As you said, your home is 30 years...

Parts of my home are cooler than others. I have vents in every room but they do not all preform equally well. How can I direct the heat to where I need it most while not overheating other rooms?

There is a science to the duct work in a furnace distribution system. For instance, if you vent a duct off the end of a plenum you will get more heat than taking the same vent off the side of the same plenum line. This is usually not something you have control over so...