FYI:
mIRC Supports the Insert/Overwrite toggle just like most other programs on window (and linux)
The button to toggle between these modes are the Insert button.
Kinda stumped that you didn't know this. Works the same way in alot of other programs, try Wordpad.
Also as for your other "suggestion" ...
Backspace = delete char before pointer
Del = delete char after the pointer
Ctrl+Backspace = delete token before pointer
Ctrl+Del = delete token after pointer
Pretty logic... again try it in Wordpad.
Also if you want to clear the whole Editbox line just hit Down.
