MacOS – Intellij KeyMapping is acting weird

Here's how you can get ⌃ Control+arrow keys to work like you describe. Copy the following property list into ~/Library/KeyBindings/DefaultKeyBinding.dict (you can create the directory if it doesn't already exist):

{
    "^\UF703" = ("moveWordForward:", "moveWordForward:", "moveWordBackward:");
    "^$\UF703" = ("moveWordForwardAndModifySelection:", "moveWordForwardAndModifySelection:", "moveWordBackwardAndModifySelection:");
}

This will set up ⌃ Control+arrow to navigate to the beginning of the next word (by using OS X's normal navigation three times: to the end of the current word, end of the next word, then back to the beginning of the next word). I also included a version that works with ⇧ Shift so you can select text as you go.

Caveat: this will only work in Cocoa apps, but I think the normal ⌥ Option+arrow navigation does too. Also, make sure to relaunch your apps!

What if you want to select 78 here (after having pressed ⇧↑)?

Or if you want to select both 12 and 78, on Windows you couldn't press shift+home and shift+end.

Methods like moveToEndOfLineAndModifySelection: are unanchored in most applications, which means that they always extend selections. They are actually anchored in Xcode, TextMate, Sublime Text, and BBEdit, but I don't know any way to change the default behavior.

If you just want to make selecting and deleting lines easier, you can create ~/Library/KeyBindings/ and save a property list like this as DefaultKeyBinding.dict:

{
    "~l" = selectParagraph:;
    "~z" = (selectParagraph:, deleteBackward:);
    "~x" = (selectParagraph:, cut:);
    "~c" = (selectParagraph:, copy:);
}

After reopening applications, ⌥L should select a line. See http://www.hcs.harvard.edu/~jrus/site/cocoa-text.html and http://lri.me/keybindings.html for more information.