It looks like they have made 1 silver the minimum deposit across the board. If you posted something prior to the patch like a fish that would have a x copper deposit, it now rolls up to 1 silver. I'm not sure if it's a display error or actually charging the 1 silver and whether or not it's working as intended.

You have the same search options through the remote AH API that you do in the web interface: you can search by item name, by category, etc. However, the neutral auction house is small enough that you can do an unfiltered search sorted by unit buyout and see anything worth sniping. There are a few reasons you might not see any sniping:
1) Nobody on your realm has bothered to write one. It's not hard at all, but if your realm is small, perhaps no one is interested.
2) There are snipers on your realm, but the goods you are moving aren't what they're looking for. Or, there are snipers, but they're poorly written. The 15 second refresh mentioned earlier does exist, and each API query takes a half second or so. There are different ways to write a sniper, with varying speed and comprehensiveness; here are a couple of possible designs off the top of my head.
-Buy anything epic under X gold
-Check each item on the neutral AH against the faction AH to see if it's worth buying. Each extra search takes time, increasing your window to recover your goods.
-Maintain a price database to determine what to buy. This is harder than the first two.
3) The scripters on your realm have moved on to better opportunities on the faction AH...