The biggest problem is the way the various parts of the settings are stored, scattered across a lot of files some of which are specific to the given character and will become "orphaned" and a new set created when transferred to a different character.
Copying the content of an existing characters "..\Anarchy Online\Prefs\<account name>\<CharID>" folder to a new char will transfer everything that's needed to make its GUI setup look like the other one (including chat windows, channel assignment to the windows, shortcutbar setup where applicable, ignore list, etc.), but also a lot of things that will not be used and will be ignored and recreated into new files (hundreds/thousands of files that will become orphaned and noticeably slow down certain client operations such as opening the inventory and bank window).
A partial transfer is also possible, if you only copy the "..\Anarchy Online\Prefs\<account name>\<CharID>\Prefs.xml" file, which will not create useless duplicates, but you'll lose the position of a lot of GUI elements; various windows, shortcutbars, chat window layout and settings...
(I have been considering creating a tool that can properly migrate / merge the prefs fileset between chars without making a mess out of it, but I'm not exactly thrilled by what it would take so I keep putting it off...
)
Edit:
I do have a tool which, while was originally created for a different purpose, can be tricked into stripping a prefs fileset of most of the char specific files that wouldn't be used on a different char anyway. It's a bit technical/complicated, but if you want to try it, I can explain what to do.