Your Flash client and a bot have one thing in common: they move around by sending x/y values to the server.
The Flash client was programmed to stop in front of walls because it loads the information about what objects are walls and what tiles can be walked over from the XML file.
A bot does not use the XML file (at least not by default) and does not know where and when to stop. It moves wherever you send it. Eventually it will get kicked by the server for doing "unallowed" things too often because the server keeps track about how long/often you walk through walls and over "noWalk" tiles ...
So you can not make a bot doing "noclip" because it is default behavior. You would need to implement walls in your bot so you can make it noclip by removing the same code ... which is just pointless.
And yes you can make the Flash client to show a "noclip" behavior. There are several ways to do that. Change the XML config. Change the XML config on load time. Change the check for "noWalk" objects in the collision detection, etc. ...