The Swiss Army Knife For Python Web Developers
This page answers a couple of questions that appeared on blogs, the IRC channel, via email or the mailinglist that cover the project as such and not specific questions to the usage. If you encounter a problem you should have a look at the documentation.
Werkzeug is German and means “tool” because it's exactly that and not a complete solution for every problem. You can use it to solve parts of the problems but you will need to combine it with other libraries to get the job done. Additionally mitsuhiko wanted to call one of his libraries like something where every non-German speaker will have problems with the pronunciation.
There are some similarities between those two projects but they try to solve different things. Paste tries to be a base library for a lot of frameworks and implements a huge featureset but is missing some handy helpers so that paste is rarely used indepenently. Separate new projects like webob, weberror, etc. try to remove some functionality and simplify the API but those projects started after Werkzeug so it was a side-by-side development.
This is a question nobody can answer for you. Frameworks allow you to get started quickly and solve a lot of problems in less time because they already combine the database adapter, template engine, internationalization system and much more. However all that convention over configuration limits you in what is possible. There are frameworks which address this problem, for example Grok which simplifies the Zope framework by preconfiguring things, but it doesn't remove all the complecity of the underlaying framework.
You don't have to know all the details of WSGI because Werkzeug does a lot for you, but since the central object, the application object, is something you have to create yourself, it's important to know that a WSGI application is a callable that is passed the WSGI environment which contains the client transmitted data and a callable which is used to start the response and returns an iterable. Additionally the response object itself is a valid WSGI application so for a simple hello world it's enough to just return a called response object in the WSGI application.