How can I make code completion case-sensitive?
I don't think that's possible.
How can I make Ctrl-k kill the content of the line and the new line character?
I can't answer that one, you might need to write a script to do it.
How can I make backspace always delete only one character, no matter what it is? Right now, it deletes spaces in chunks equal to my indent level.
Backspace always deletes one character. It sounds like your file has tab characters in it, each one of which takes up the space of 4 spaces by default. You can tell Xcode to use spaces instead by de-selecting Tab key inserts tab, not spaces in the Indentation preference panel.
How to change the indentation style in file templates? I like to have the opening brace on its own line.
You need to create custom file templates. You can find the Xcode templates here:
/Developer/Library/Xcode/File Templates
You need to copy the appropriate templates to this location:
~/Library/Application Support/Developer/Shared/Xcode/File Templates
You can then edit the template files to use whatever indents you like.
How can I make the font aliased?
You need to use a font that has aliased characters. Try Monaco at 9 or 10 points.