Lost

Am I being over sensitive here? I am feeling so lost when I interact with people. I blame it on my living condition at the moment, living with my parents. It's like the Twilight Zone.
 
The newest issue is my parents are installing a new bathroom. I heard them talking about it a few day ago and things they said really raised a red flag. They were going to make some key mistakes working on a project they know little about and so I offered to help. I told them, "You know, I totally gutted and remodeled 5 new bathrooms when I was hired to remodel a mansion of a house a friend of mine bought two years ago."  My mom laughed out loud, as she often does when I offer advice, but I continued, "Yes, I did everything, from the plumbing to the electrical, right down to the towels." I then gave them advice on what I thought were some mistakes they were about to make.
 
So today I found out my dad had asked my brother-in-law to go with him to get the hardware including sink, shower, etc. These two guys are nice guys, but the two biggest rednecks I know. And as expected they brought home things that won't fit, won't work, and nothing matches in color or style. I didn't say a word, I just took it all in and laughed inside. It's like I am hoping they will fail. Evil of me, right?
 
So anyway, I don't know if I have a right to feel insulted or slighted here. Am I just depressed or should I step up and say something to them? What I want to say is, "Look, you're  doing something here that you are going to have to live with for a long, long time and it needs to be done correctly. You're going to end up unhappy with how it looks and functions for years to come."  I am sure they will all just roll their eyes but I feel I have to get it out.