Answers (and some questions) currently use a mix of simplified and traditional characters. Should they be edited to provide both, and if so should we adopt a uniform convention for doing so (e.g., parentheses)?
This may be anecdotal, but I can't read traditional characters. Therefore, any answer that is written in traditional characters is somewhere between useless and time-consuming to decipher for me. Most people I know that read traditional also read simplified. Therefore, I'd say that answers should be written in the same kind of characters as the question, with a preference to simplified characters if there is a mix, or if the question seems to be from someone who doesn't know the difference.
The answers given mostly state that simplified characters are the minimum baseline that most people understand, so they should be preferred over traditional ones. And I agree.
But the OP asks about editing Q/As to add the character version that is missing, so it won't affect people that already know how to read the original character, but it will add legibility to people that can't and instead does read the added version of the character. Or to those curious about the version of the character they don't yet know.
To which I agree. In this case more is not less, it's more :)
Perhaps we can just ask the authors of Stack Exchange to add some processing to automatically insert 繁体字 that appears in a mouseover if the original post had 简体字, and vice versa. Speaking as a programmer, automatic transformation from one to the other is straightforward. Who do we contact for adding features to Stack Exchange?
From the questions, traffic and people answering the questions so far it appears to be overwhelmingly about Mandarin which I would expect to continue to be the trend considering this site is for learners and there is a much larger base of people learning Mandarin than there is Cantonese or any other dialect.
Secondly, most of the people who can read complicated can read simplified, it's not that hard.
Thirdly, there is a large overhead in terms of redundancy, see your question for example 2/3 of the characters are the same.
Echoing what others have said, it is hard for people who learnt simplified to read traditional and vice versa - especially given that the majority of people who ask questions will be learning Chinese.
For beginners like me, seeing a paragraph written in Chinese is already daunting enough - let alone in one that is written in the script we haven't really learnt!
The problem with having answers written in the same form as the question is when someone else with the same question (but has learnt the different form) comes along, they'll find it difficult to read both the question/answer.
Maybe some way to easily access Google translate (to convert between Simplified<->Traditional)? http://translate.google.com/#zh-CN|zh-TW
ps. I'm in the process of learning to read/write Traditional (and recently to read Simplified) and I've found simply by converting a passage from Simplified to Traditional I can understand about twice as much (which makes a huge difference!)
The main problem would be that it would get really confusing for people who are still learning Chinese, while providing both leads to distraction easily.
I am suggesting that the website itself should be coded to automatically underline characters that can be translated to simplified or traditional Chinese, and the other version would be changed when that word is clicked (not mouseover, because mouseover and hence cursors seem to be deprecating in the development of technology (title text of https://xkcd.com/1683)).
For characters that can have the same word in traditional Chinese, such as 只 is the simplification of both 只 and 隻, maybe allow the author to put a backslash before a real 只?
There are differences in commonly used words in different regions.
小姐 means "Miss" in Taiwan and is used widely every day. You can try to call a female 小姐 in China and see what will happen.
The sentence, 你吃飽了嗎？ is a greeting in Taiwan. But it seems to be a bad sentence in China.
Therefore, I suggest that the users should use their own glyphs, TC or SC, so that the readers can know where the contents come from.
I think it's readers' responsibility to convert the glyphs.
1. The above reason.
2. Be independent. Don't rely on anyone.
3. You will read the other glyph sooner or later.
4. You are the one who is learning Chinese.
5. There are good converters out there. Why don't you install one of them?
It's better to use a converter that is an extension of your browser.
1. Faster. You don't have to do the copy-and-paste.
2. Complete. The whole page can be converted. You can see only the copy-and-paste part with an on-line converter.
By the way, if you obtained what you wanted to know from an answer with the other glyph, you should accept it too. The users take their precious time to help you, you should appreciate them too. Right?
While agreeing with the advice (of using the same kind of characters) in bolded text in the accepted answer, there should be one exception: for posts whose context is about the comparison of traditional and simplified characters, one can provide only one kind of character.
For example, in my recent meta question, I've quoted a poem found online.
The mixing of simplified and traditional characters plays an essential role in illustrating the main ideas of this poem. In my meta question, I didn't write "patriotism" (爱国) in traditional characters in order to show the absence of a "good heart" (良心) in the simplified writing for "爱国".