Eclipse questions for a Visual Studio programmer (using Javascript Edition + pydev)

I am new to eclipse and am using it for Google App Engine development. I come from a Visual Studio background. I installed following edition of eclipse from this link:

Eclipse IDE for JavaScript Web Developers.

Version: Helios Service Release 2

Build id: 20110218-0911

I also installed pydev on my machine. I have several questions:

1. first, it seems i can't run multiple instances of eclipse w/o creating multiple workspaces ref. what is the procedure to work on multiple solutions (.sln in VS parlance) when using eclipse?
2. i created a new pydev project. how do i add existing javascript files to this project? can't figure this out. Will i have to keep my javascript code sequestered from my pydev project?
3. finally, when browsing the workspace i see a .project and a .pydevproject file but neither of these files contain instructions on what files to include in the project. what are the equivalents of the VS .csproj 开发者_开发百科and .sln files in eclipse and where to look for them?
4. Does the edition I am working with have built-in intellisense (known as code-completion in eclipse parlance) support for jquery? if yes, how to activate it as it doesn't seem to be working for me. if not, is it possible to download some lightweight plugin and get this functionality?

1. You can have several projects in a single workspace. You can open as many as you want. In fact there is no reason to close the project except little performance gain and usability of views.

2. Copy your files to the project folder and refresh it in eclipse (F5). The alternative is choosing location of your project when you create it. You may need to configure source folders if your directory structure is not guessed by eclipse correctly.

3. Eclipse picks up all files in a folder and so doesn't store them. Some project configuration can be found in the .settings directory (additionally to .project and .pydevproject). The rest is taken from the eclipse-wide settings which are located in .metadata in human unreadable way.