Hi Andrei,

re: Is it possible to use - Left, Right, Up, Down keys for shortcuts?

Yup, in the help file topic for Shortcut keys, there is a list of all the key names you can put in:
http://moi3d.com/3.0/docs/moi_command_reference11.htm#shortcutkeys

"The key can be defined using a letter (like "A") or one of these labels: F1 - F12, UpArrow, DownArrow, LeftArrow, RightArrow, Home, End, PageUp, PageDown, Insert, Delete, Backspace, Space, Numpad0 - Numpad9, Numpad.*+,-/ . The key can be prefixed by one or more of these modifiers: Ctrl+ , Shift+, or Alt+ (or Cmd+ on OSX)."

- Michael