Did she give me a detour kind of "short cut", or did she just cut off my balls?
If we prefer not to say "shortcut", then at least say "short-cut". This way, the adjective "short" is co-joined with "cut" to indicate that they are connected. This guarantees that the "cut" is associated with "short", and not whatever word comes after.
If you don't have a colon between the "Frame Rate Display" and the combo box, then it just looks like the combox box is randomly placed there and unrelated to the checkbox you just checked/unchecked.
If "fullscreen" was a valid word, it would be an adjective, not a noun. You cannot "go to" an adjective because adjectives are not places, people or things. So it should be "enter" as in "enter a mode" (such as a full-screen mode), not "go to".
"Use high-level-emulated audio" does make sense, but seems a tad bit strong (and people could mistake the "high level" to mean extra/better emulation without any scientific HLE understanding). So I think "Audio HLE" looks better.
Either say "Percentage", or just drop the '%' since this symbol of unit is not relevant to what the menu item should convey to the user. What we're really trying to do is show the CPU usage statistics...most likely the users would see for themselves what unit it comes out as (percentage, fraction, whatever).
"On" is a preposition shorter than 5 letters long. Standard title case does not ever capitalize short prepositions (unless they are the very first word of the title, then usually). You can see this logic in the Visual Studio 2008 IDE itself: It has menu items such as "Attach to Process" and "Find[/Replace] in Files", in which the prepositions "to" and "in" are, correctly so, not capitalized by Microsoft in the VS2008 menus.
Nekokabu