The first one might be a duplicate to some others, but if you edit it and write a good answer, we might use this as a canonical target for this kind of question, which appears semi-regular from new users/admins. However, personally I would rather have a new question for this purpose though (maybe as community wiki), to avoid the situation with the compromised server question which started as a normal question from an unsuspecting user.
I don't believe the second question is fixable, as the list of things to consider is potential endless and highly dependent on the specific environment. Also, I am not sure we should have an answer that would need to be too broad itself as a dupe target for a question that would be closed as too broad otherwise.