/sigh I guess its too much to hope ppl might actually look at the names of the 5 newest files and notice one is named eq2ui_mainhud_mainchat.xml. Or maybe check the add-ons for a chat window.
If you're not happy with the stealth input, you can install the 3.4 version of eq2ui_mainhud_mainchat.xml or this
add-on version that only hides the scrollbar.
Personally I don't find it at all annoying to mouse over the main chat window on the rare occasions I actually need to see what I typed (90% of the time its short 5 word blurbs I can type blindfolded).