Chances are, you may not get satisfying answers to all of your questions. However, having this conversation with the technician, is the only way you’ll know better whether you should trust your vehicle to this specific auto repair shop, or not. It will also adjust their mindset towards you as they will realize that they are dealing with a serious customer who takes his/her car maintenance seriously.
Finally, when in doubt, always ask for a second opinion. Especially when the suggested cost of repair is really high. Because in the end, you are the one who’s going to pay for it.