1.6.0 is on the store, and most of this list is in it.
Categories that hold nothing but other categories
Every category now has a switch, "Members may post listings in this category", on by default. Turn it off and the category still shows in the tree, still groups its children and still keeps anything already filed in it, but it stops being offered as a place to post and nothing new can land there.
DocKnight, that is your Coins & Precious Metals over US Coins and World Coins, set in one click rather than by unticking listing kinds.
St. James, it is your Ball-Jointed Dolls over Full Dolls, Heads, Bodies and Parts too. You can see it running on the demo: Gaming is now a container with Consoles & handhelds and Controllers & accessories under it, and the post form shows the parent greyed out with the children selectable under it.
St. James, on the price guide, child categories should give it back to you. The guide only ever looks at the listing's own category and the categories under it, never at the whole tree, and it narrows further by the custom fields that are filled in. With $5 heads and $5000 full dolls in separate child categories the median stops being the nonsense you were seeing.
Posting from inside a category starts you in that category
Open a category, press the post button, and the category is already picked. A container is never pre-picked, so you land on the form with the choice still open rather than filed somewhere you did not choose.
The three phone problems
The listing page now reads photos, then the price and the buttons, then the details, then the rest. The details no longer sit at the bottom under the whole sidebar.
A finger swiping up or down over the photo carousel scrolls the page again. Sideways still moves through the photos.
The location and distance filter stacks into two full width rows on a narrow screen, so the distance box is no longer pushed off the edge.
The listing allowance
DocKnight, this one is XenForo's own rule rather than mine, and my wording sent you the wrong way.
For every numeric permission XenForo looks at all of a member's groups, primary and secondary alike, and keeps the highest value. If any group has Unlimited ticked, Unlimited wins outright. A permission you never touched reads as 0, which is why 0 cannot mean "no listings at all": every group that has never seen the setting would be locked out.
So your Registered at 1 and Administrator at 0 gave you 1, because 0 was not a bigger number, it was "nothing set here". Tick Unlimited on Administrator and you get unlimited. Add a Verified group at 5 and a member in Registered plus Verified gets 5. Primary and secondary make no difference.
The behaviour has not changed in 1.6.0, but the labels have: the three numeric permissions now say "tick Unlimited for no cap" instead of "0 = unlimited", which is what misled you.
The global expiry is already there
Admin CP, Options, Classifieds: set how many days a listing stays on the market. A listing past that date goes to Expired and leaves the market, and its owner gets a Renew button on it that puts it straight back on sale for another full run, with nothing for you to approve. There is a separate bump, with its own cooldown, for pushing a listing back up without waiting for it to expire.
Still to come, in the order I plan to do it
1. Hiding the condition field per category. You are right that it is all or nothing today, and switching every condition off in the Admin CP leaves an empty dropdown rather than no field. This is the next one.
2. Miles instead of kilometres, with a unit and currency default that follows the board rather than being set listing by listing.
3. The custom field suggestion list that covers the screen on a phone and then hides the keyboard when you scroll it.
4. Quantities, where a sale takes one off the count instead of closing the listing.
5. One more level of nesting, with the tree drawn the way XenForo draws the node list.
If the order is wrong for your forums, say so in this thread. It is what I sort the work by.
