I have mirrored all maps on some hdd. Not sure about voices, but at least I have mirror or polish/english.
And about apps/games I strongly believe I have the most complete mirror of full versions (including rare stuff like OBD Auto Doctor Pro, Nokia Car with Mirrorlink, etc). I was unable to find 3-5 debs generally and never cracked FM Radio successfully(I bought it, but wanted to move to other N9s I bought after store closure).
I've mirrored multiple n9 archives in the past, so there are many dupes, etc needed to be cleaned up before uploading. I hope I wil buy some 12-14TB drives to move data from many smaller drives and organize/dedup it as one big categorized archive.
But don't worry, I will never delete anything n9 related!