Angular 2.0 - Components vs Directives

I am totally new to Angular 2.0 with Typescript and just started liking it.

I have few doubts:

1. When to use a component and when to use a directive?

2. Can I assume every new page I create, be an individual component?

3. Best responsive UI library to work with (A 2.0 + TS)?

4. Best REST client libraries, that add more RESTful features support A2's existing Http module?

5. Easy ways to debug an (A2+TS) application? When ever I make any single simple mistakes, the browser just throws me ' Unexpected character < ' error when the app is ran.!!! :(