I am on Mac OS X, and no matter what I change in Keys in Preferences, I get highly unorthodox and to me completely alien behavior where the selection changes to engulf the wider parent scope (in brackets). I am used to other editors where holding Ctrl+Alt and left or right arrow key moves selection endpoints and the cursor across word boundaries. Is there any way to achieve this behavior?
Eclipse allows you change key bindings for commands. For example "Previous Word" command can be changed to Cmd + Left Arrow.
From the wiki...
Display and Edit the Current Keyboard Shortcuts
To see the current key configuration and its keyboard shortcuts, choose the Eclipse > Preferences menu command to open the Eclipse workbench Preferences. Select the General > Editor > Keys page.
Type "Previous Word" in the command search, then click on the "Binding" field. Then do the key (e.g. Cmd + left arrow) then apply.