Encrypting the wallet only works when I'm not using my money. In the case of Visa I can use my card to buy a 2,000 computer system online and if a hacker gets my number I can dispute any charges with Visa. If I decrypt my wallet I automatically make a point of failure where a hacker can take my money. If I put my bitcoins into a third party and the third party is hacked then my money and everyone elses money is lost.
Now with metadata I can still lose my money in all the examples but if a bitcoin cashing place gets bitcoins that were owned by John Doe and the person wanting the cash is Jane Smith then that may put up some red flags and the cashing place can invesigate that.
With today's technology you can create a Fort Knox to hold your Bitcoins in your home.
Truecrypt + Virtual Machines + Linux are the things you need.
With these, it is possible to create a digital safe with multi-level encrypted rooms full of mirrors & traps/honeypots which only you can navigate and only you know if they contain anything.... Possibilities are totally endless.
PS. If you want to go "security", drop Windows & Mac instantly. Go Linux or BSD. Corporations such as Microsoft & Apple can not be trusted. Actually, no corporation can be trusted and that is why we have open source software.