In Ad Hoc, I can select Hour/Day/Month as a dimension but they are always stored as the exact calendar date. If I want to compare the months of two calendar years against each other, it would be useful to have a dimension that only stores the month. That way I can build tables with year in the colum...

The Request Manager (and with it the Data Warehouse) would become a lot quicker to use if we were able to filter on specific kinds of requests only. I am able to search for a specific user's  report or report name but I can also see scenarios where searching for a segment, a status or a  combination...

Is there any way I can create a segment (or filter) on Bounces only - or conversely on Visits that are not a Bounce? We can filter on Visit Depth = 1 but I suspect that the results are different from what a segment actually on bounce rate would show.

Yes, that top-down approach would work but it would involve a lot of curation and making assumption by our admins. The bottom-up approach would be more convenient in our case.

Across all our teams, we need a large number of segments but any single user only needs a fraction of them while the rest creates unnecessary delay or ambiguity. It would be useful if each user was able to set segments as Hidden, so they don't clutter up the list of segments when they create reports...