Read the Kix2010.doc. It is not that big and it contains all the answers.
Code:

If NOT @LOGONMODE
	Break On
EndIf

If you break a KiX script, per default KiXtart will log off your computer. This is OK for login scripts. But for other purposes, most of the time this behaviour is unwanted. Take a look at the vivid discussion: Break On should be the deafult.
Code:

Dim $RC
$RC = SetOption("Explicit","On")

If you do not Dim a variable, it is global. I prefer local variables to avoid confusion. The Explicit option forces to declare variables.
Code:

$RC = SetOption("NoVarsInStrings","On")

If a $-sign is used between quotes, KiX tries to translate it together with the trailing chars to a variable. You would have to double the $ ($$) to show it is not a var. Only exception is when the $ is at the last place of a string, e.g. "\\Server\HiddenShare$" or "This is a $ symbol". Setting the NoVarsInStrings option makes that a $ between quotes is always a part of a string.
Code:

$RC = SetOption("NoMacrosInStrings","On")
Code:

If @ is used between quotes, KiX tries to translate it,together with the trailing chars, to a macro. you would have to double the @ (@@) to avoid it.
Setting the NoMacrosInStrings option on does just what is says: No Macros In Strings.
Code:

$RC = SetOption("WrapAtEOL","On")

If screen output is wider then the character width of a command window, the same line is overwritten. The WrapAtEOL option adds a crlf to the character at the end of the line.