Ok, it's certainly good to know your limits. However, I had never done anything like that before either, and it was really no problem at all. Since I am also cautious with water, I had all the water pipes installed by the company. If the connection of the mixer or something like that is still leaking, you can always get to it easily, so that wouldn't be such a big disaster. But as I said, it's good to know and respect your abilities and limits. Whether tradesmen install foreign things for you is probably a matter of negotiation. But if the installation fee rises accordingly, of course it no longer pays off.
