These kind of questions are border-line, aren't they? Back where I come from, these (rock climbing and sky diving) are not considered sports but just activities done for fun and thrill. I think these fit perfectly into the The Great Oudoors and my opinion would be to proactively migrate future questions to TGO SE.

@edmastermind29 IMO, a transaction tag would be very vague and I don't think an author would easily connect this with the transfer window. Would you rather have separate transfer and draft tags? Coz, technically, they both are different.

It's a start. For the "not-to-be-asked-here" questions, we can have a look at the closed questions on Sports SE and make this list more comprehensive (Example: The recent spate of 'jersey number' questions and 'Why is so-and-so called so-and-so' questions). This should give some directive to the new users (Provided they read the FAQs before posting questions) on the type of questions they should NOT post.

I think the acronym EPL is recognized in most football playing nations. The FA tries to market it as BPL (Barclays Premier League) for sponsorship reasons but it has not taken off and the league is still famous and mentioned as the EPL worldwide. Have to agree with posdef in saying this acronym is not ambiguous. However like @Bernhard suggests, editing tag-wiki should help in sorting out this issue.