A sysadmin who goes about changing the production environment without a change plan is a sysadmin who is more of a liability than they are worth.
That might sound like an insult, but it is a hard fact. A sysadmin's primary job is it provide a <emphasis>stable</emphasis> environment for the users of that environment. Given a stable environment other things can be done like running production applications that make the business money. That's the whole point of the exercise anyway. Isn't it?
Before making changes on a production system they need to be tested on a <emphasis>test</emphasis> system that closely mirrors production. That way when they go into production you know what to expect and can plan for it. In any case, you need to have a backout plan, yes even for the test system, in case things go south.
It seems to me that much of your grief comes from a lack of planning. Expecting to be able to upgrade software, any software, and expect everything to continue to work the way they always have is foolhardy. Newer isn't better until it has been proven so.