Monkey Tools contains a collection of Sleuths who can help audit your workbooks, as well as make changes when desired.
While there are far more than just two things that drive me crazy with Power Query, two of the biggest have to be that 1) the Query Dependencies view doesn't work well on complex query chains, and 2) you get locked out of Excel when you open the query editor. In this video Ken introduces you to tracing query chains on simpler models, and shows how the Query Sleuth not only displays M code in an indented format, but also allows you to make light code edits WITHOUT EVER ENTERING THE POWER QUERY INTERFACE. That's right, you can still interact with Excel while making those edits!