I actively encourage the editing of any of my Question, Answer, and Tag Wiki content on all StackExchange sites except for meta sites. In other words, if you spot an inaccuracy or wish to clarify or improve a post of mine, add sources, etc., PLEASE do so! It will greatly benefit the net welfare and knowledge capital of the community. I am writing this here just in case you are of the misconception that answers are like forum posts, indelible articles authored by a single person.
The edit function is there for a reason, folks. I promise to never lash out at someone for substantially editing content originally authored by me, as long as your edit is constructive. If you don't yet have the site privilege to make instantaneous edits and I see your edit in the suggestion queue, I will do my best to either accept your edit outright, or incorporate the most useful parts of your edit into my post by "editing your edit".
If you have been told before that you shouldn't substantially edit others' answers, or if you've been the victim of polemic as a result of doing so, I'd like to apologize for that behavior. I think it's very counterproductive; our community is much worse-off for that kind of attitude.
Future visitors are best served by being able to read one cohesive, well-edited answer with sources to get the sum-total of the community's best knowledge in a single answer. A string of answers or comments each with their own nuggets of truth is much harder to decipher than one cohesive text. With the edit function, thanks to the fact that we each bring our own perspectives and unique knowledge, it is possible for us to author one cohesive text that eliminates the natural tendency of comment strings, replacing it with high-quality works that rival those of Wikipedia.
BTW, I don't approve of most edits on meta sites because I very rarely find questions on meta sites which deal purely in factual matters, so my answers are generally just my personal feelings on the matter.