About one you need to set the app as device owner, it's quite tricky so be sure about what you do. You find instructions in the app, there is an "how to" button. Then you can use the "Keyguard" action to enable/disable the swipe-to-unlock. If you disable the keyguard and you have currently a pin/fingerprint or whatever your phone will be set to "none" as security pattern. If you turn on the keyguuard you set the pattern to "swipe". To restore the pin/password you can use the "set password" action. Before to use this action you need to set the pin/password in the app, there is a setting about it. That's all. The tricky part is at the beginning to set the app as device owner.
About the point two: you need to grant some permissions using a pc, connect the phone to a pc with debugging usb enabled (you find the options in the developer settings). Install adb (and the needed drivers if you use windows) on your pc and then use a couple of commands, the commands are described in the "how to grant permissions" menu in the app.