Where is the config (application properties) file for TimeMachine settings and the path excludes?
ok, found it:

/Library/Preferences/com.apple.TimeMachine.plist


They ARE saved in the Systems-Library Preferences. All user settings are entitled in this file ;/

see http://hints.macworld.com/article.php?story=2010051917410348 => http://hints.macworld.com/article.php?story=20071207104354466



P.S: According to @M-K's answer the default exclusion list is found under

/System/Library/CoreServices/backupd.bundle/Contents/Resources/StdExclusions.plist