- Bugs and feature requests are not answerable in the StackExchange definition of an answer. They're out of scope for a Q&A page.
- Close/flag those questions as off-topic, but explain to the inquirer why it is out of scope in a short, but appropriate comment.
The problem with bugs and feature requests
There is no clear answer for people inquiring about bugs. Users are experiencing bugs because they're not fixed yet. Only in a few cases there are workarounds available to (temporarily) solve the bug. There simply is no satisfying answer possible to a question about "How to fix bug X?".
Feature requests are not really a question according to the definition of a StackExchange question. Questions should have answers that are helping the inquirer with his desired outcome, but the only answer possible to a feature request is "that is not implemented yet, please file a issue on Launchpad". Additionally, while this community is currently moderated by 2/3 elementary OS contributors, it's no "official" community operated by elementary LLC. or any other official representatives - The community cannot help with introducing new features, that is up to the elementary OS contributors.
In general, StackExchange is of course no place to track an issue properly anyway. That's just not within the scope of its functionality as Q&A platform.
How to handle these questions
A lot of these questions are asked by people unaware of it being a bug that is not fixable or a feature not implemented yet, they assume there could be a fix for it. We shouldn't just close these questions without any comment, because that's confusing and even rude for community members inquiring about a valid concern.
But, as there is no real, helpful answer, these questions should be closed to prevent low-quality posts and to bring "this is not the right place for that" to mind. This action should be prefaced with a comment explaining that this is an issue without answer and should be reported on Launchpad.
It is possible to create custom reasons for a question closure as a moderator. Flagging this a duplicate seems confusing and not really appropriate, therefore we should consider to flag these questions as off-topic with a custom reason for bugs and feature requests provided by us.