“Error: Options Page Not Found” on Settings Page Submission for an OOP Plugin

I am developing a plugin using Tom McFarlin’s Boilerplate repository as a template, which utilizes OOP practices. I’ve been trying to figure out exactly why I’m unable to correctly submit my settings. I’ve tried setting the action attribute to an empty string as suggested on another question around here, but that hasn’t helped…

Where to securely store API keys and passwords in WordPress?

I’m looking to use a few APIs and many come with keys, secret keys and passwords required to work. Where in WordPress can you store that information? Assuming anyone can hack your DB is there anyway for WordPress to make saving that information more secure? Also, consider the ability to change these keys ever so often so I would need to update the keys on an options page.