You can press the "Disable smileys" checkbox in the posting screen to...well, to disable smileys.
You can press the "Edit" button after you have made a post if you need to change some part of it, rather than double- or triple-posting. The "Edit" button is in the top righthand corner of every post you make.
Mine looks like this:
. Yours probably looks a little different, but it's in the same place, at least.
Welcome to PPT, by the way.
There is no way to tell how much time is remaining in an auction, because there used to be players who would use a program or just their own fast connections to outbid other players for auctioned items when they had one or two seconds left. The Neopets Team (referred to frequently as TNT or the NPT) responded by reducing the info displayed on the screen.
The best way to win auctions, if you really want an item, is to just bid what it's worth, or a little more. Check on an auction every so often to guess-timate how much time is left, and be prepared to bid again if someone outbids you.
For most items, buying them in user shops is a much better way to get your hands on them, and often cheaper. You can search user shops using the shop wizard. To get a better range of prices, press the F5 key to refresh the shop wizard search screen - you'll get a little popup that says you'll have to refresh the search, and that's what you want, so hit OK, or just hit Enter.