Well, the first two are perfect and are synonymous with each other. "in any case/event" is an introductory phrase that signals a conclusion to the topic under discussion. This phrase would not be used without a preceding line of thought.
The last three statements lack this kind of introductory statement that signals that a line of thought is being brought to a conclusion. Instead, the three adverbs (-ly words) merely underscore the strength of the statement. The sentence with "surely" sounds slightly less natural than the rest, only because I have trouble imagining a conversation in which an American speaker would say this rather than "certainly" or "definitely" -- but that is only my opinion!