Version: (using KDE 4.3.0) Find pane contains two options put into popup menu -- so it is ration 2:1. Such ratio from usability POV indicates that those options should be presented directly not via popup menu. Also with benefit for user to being able to read them right away, without opening menu for that purpose (checking in what mode the search works). When you look at find next button and previous you will notice that it all fits nicely into customizable toolbar -- i.e. configuring the size of the icon and configure the placement (if any) of the text -- under the icon or next to icon.
Add all of them inline would just kill the horizontal space available, especially on long translations. Also, we're behaving like kwrite/kate currently.
See above -- in the wished UI there could be no text, it would be up to user how to put this. So more elements does not mean more space taken (currently okular uses "label next to icon" buttons which takes space).