The next file contains menu items that can also be translated pretty freely, but great care should be taken to make sure menu items don't have conflicting shortcut characters. They must also keep the same Hotkeys.
What exactly do you mean by 'hotkeys', the key combination like ALT+B, or the underlined character? I think the key combinations should stay the same, but the underlined characters don't have to.
I am dutch and use my parents pc, so I see quite some software that has been translated to dutch. And half of it has been 'over translated': almost every word was translated, like 'file'->'bestand', 'directory'->'map' (from 'folder' aargh) etc. I'd hate to see someone come up with translations for 'alias' 'remote' etc.
I'm also making a script that uses language files. The greatest problem for me was that the dutch text somehow always seemed to take up more space then english. Since I was still developing the script I could easily make room for this, but I think this would probably become a problem when translating mIRC. Translators will probaly have to come up with creative solutions, or Khaled would have to enlarge a lot of controls, which would probably mean redesigning a large part of mIRC.