Help with automatic shutdowm and user control

Hi!
I am quite new to Mac and recently bought an iMac. I have a couple of questions about automatic shutdown and user control.
I would like to make settings that mi computer will shut down at a certain time of day and automatically power on at a specific time. I have tried to do this in the systems settings but as I have multiple user accounts on the computer and all of them are almost always logged on the settings won’t work because then I get a prompt that tells me to enter the administrator password and username. IS there any other way to do this? Maybe another software?
The second issue I have is that I as mentioned before have multiple accounts active, me, wife, kids. When we sit by the computer we simply switch users. The thing is that when I want to switch back to my user account I have to enter my password. I would like to turn this off somehow. The option of automatic log on without password that I activated in the systems settings only automatically logs me in when I start the iMac.