Very sorry to hear you feel that way. I would however point out that we cannot know for certain if an upgrade will break your site. The notifications are actually optional to be received by email. Click the bell icon in the right of your admin CP, and deselect that email option. The dismissing of notices in the admin CP, you can do, but it will eventually reappear. The exception to this is security updates, which you cannot dismiss. I would point out however that only admin can see these.
CiC is a great solution, however unfortunately if you are looking for software which has no upgrades and can guarentee 3rd party items wont break it, then CiC is not something that is going to resolve that.