Putting special characters in the title should have no adverse effect on the layout or functionality.
Special characters in the post title have been known to cause issues with JavaScript when it is minified, especially in the admin when editing the post itself (ie. issues with metaboxes, media upload, etc.).
Super/Duper/Long/NonBreaking/Path/Name/To/A/File/That/Is/Way/Deep/Down/In/Some/Mysterious/Remote/Desolate/Part/Of/The/Operating/System/To/A/File/That/Just/So/Happens/To/Be/Strangely/Named/Supercalifragilisticexpialidocious.txt
Super/Duper/Long/NonBreaking/Path/Name/To/A/File/That/Is/Way/Deep/Down/In/Some/Mysterious/Remote/Desolate/Part/Of/The/Operating/System/To/A/File/That/Just/So/Happens/To/Be/Strangely/Named/Supercalifragilisticexpialidocious.txt
A few things to check for:
The following CSS properties will help you support non-breaking text.