1.) Are frameworks written to be streamlined, or do they bog down your servers because they contain so much unused code
Naturally yes. Frameworks, libraries or platforms all abstract details from you as a developer so you can focus more on value added features instead of infrastructure and boiler plater code.
2.) Are frameworks written to assist those who do not know php get their projects completed more easily?
Frameworks, not so much, they typically provide a high level set of common software patterns, and usually understanding patterns, the motivation behind them, you probably need a few years of programming experience to appreciate what they do. Libraries usually hide details particular to very specific units of functionality, such as PDF generation. Instead of learning the ins and outs of PDF spec you can use a high level API to build documents instead, so in that case, I suppose libraries help. Platforms, in the web arena, such as WordPress/Joomla/Drupal/etc are meant to make specific types of web sites or apps easier to build and in some cases without any programming required, although having a background in PHP certainly helps troubleshoot issues when they arise.
3.) What are the benefits of most common frameworks Laravel and Phalcon (Best PHP Frameworks 2014)
Please avoid using the term "best" it's very subjective. Answer the question by asking yourself about personal requirements and possibly project specific. How important is performance? If it is paramount, than Phalcon (being compiled extensions) is the winner, but if portability and resale to multiple clients is most important, than something purely PHP is a better alternative (ie: codeignitor).