I love meat, I like a good leather jacket. I want a world where we take good care of our animals, take no more than we need and then use the entire animal as efficiently as possible. Reality however is a lot more cruel and wasteful. It is everyone’s personal choice but I chose to stop purchasing cow and pig products.
First and foremost, the user that adviced you to look at the connection speed is 100% right. If you establish a gigabit link with a gigabit device, it makes no sense to upgrade other than future proofing.
There’s no point in going beyond Cat 6a. Keep in mind that the length of the cable is a big factor as well. For 1/2.5GbE, Cat 5e is plenty (for at least 100m). If you plan on going to 5/10GbE now or in the near future, Cat 6a will get you there with ease (for at least 100m). In both cases, keep the cable as close to the required length as possible + a 30cm/1ft service loop (slack) on each end. That will cause no more signal degradation then necessary and make for a clean install.
Only on holidays. If I pick up some furniture, I don’t bother, but when I’m driving for one or two days straight with 4 people and luggage in the car, yes definitely. It helps that I can check/adjust my tire pressure where I wash my car every two weeks. I’m really particular about the handling of my car and the tires I drive on, so I’m always on top of the correct pressure.