I'm trying to work on my query still, but what I've learned is this. By far, the most popular tag for first time users to this site is story-identification. Note that I make no difference between questions and answers with my query. The second column shows the average number of posts per user, including the first one. Looks like Story-Identification doesn't ...
Some of these queries already exist. However, I made a slightly more at-a-glance version that captures average score, as well as average upvotes and downvotes for both questions and answers.
The usual SEDE disclaimers apply here:
It only updates once a week (usually Sunday morning, depending on your timezone), so it won't include any questions ...
Ask and ye shall receive
Standard SEDE disclaimers apply:
Updated once weekly; currently we're about two days behind reality
Doesn't include deleted posts
Plug your SFF UserId into the box and away you go.
Mine is 0.453
Yours is 0.111
Valorum's (since he asked) is 0.047
Note that this hasn't really been tested, since I'm not inclined to manually count ...
TL;DR: Here are the queries:
Top users in a tag by score and answer count
Top user in all tags by score and answer count
Tags where specified user is top by score and answer count
This can be done using SEDE! However, to be clear that there is a slight limitation in that SEDE only updates once every week.
How often is the Stack Exchange Data Explorer ...
You came closest to the mark with this:
My guess is that many of these posts were due to a very busy troll
Suffice it to say that a large number of offensive posts, mainly attacks against a particular pair of users, were created and subsequently destroyed on 22 August 2015. The many different accounts used to make these posts no longer exist.
As has been mentioned in the comments on your question (e.g., by AncientSwordRage's Meta.SE link), it's not possibly to dynamically query the data explorer.
It's also not possible to embed runnable code in answers; in principle it looks as though Stack Snippets can be used to query the API, but of course we don't have Stack Snippets enabled, nor ...
As you suggested, we had "a very busy troll".
Without getting into the details, the incident was dubbed "sock fest". A user believed he/she had been treated unfairly and retaliated by creating dozens of sock puppet accounts and making malicious posts.
Most common tags with short, long, or missing excerpt or wiki: You can browse tag wikis by tweaking the first four parameters on this query.
Related tags: Browse the full list of related tags for any tag.
Search posts with a specific post type ID: Mainly useful for searching tag wikis.
Tags with the most views per question: See which tags are most ...
Sure. Nice one-liner to paste into the Data Explorer:
SELECT AVG(Score) AS [Average Score] FROM Posts WHERE OwnerUserId = ##UserId:int##
Provides an average score across all posts. If you want to filter to post types, you'll need to add another constraint.
N.B. Will always output an integer, because of integer division. Can be worked around, if necessary.