Thanks for your critics! My service would be more like a wallet backup service. You still have your wallet on your PC where you do your payments, speculations, etc. So this is more like an ultra-safe wallet backup than a cloud wallet or something similar.

To answer your questions: Every wallet file (or text file with private key in it or whatever the final solution will look like) has to be encrypted by a strong password, so that even if someone would manage to find out that there are Bitcoins stored in the bunker (very unlikely) AND if someone would pass all the security barriers (like video cameras, security guards, multiple steel doors that are locked, etc., which is extremely unlikely), he couldn't do anything with the files. Also, I plan to contact another two companies that do the similar thing (ultra-secure bunker place rentals / IT bunker solutions) to not only have the files redundant in one bunker, but also have them redunant in more bunkers. However, I would need to contact and meet them to ensure maximum safety. I have done this with the current bunker I know, I also have a few personal contacts to this company.