Clean up get() calls, remove commented out code

@Ignat99 PTAL.

As suggested by @dionyziz at https://github.com/OpenBazaar/OpenBazaar/pull/658#issuecomment-56653243 I created a PR out of my own code-review comments.
@Renelvon 
>  this will break code that explicitly tests for None in the absent fields.

OK. Changing it.