Please don't sync yet, it's currently in a mixed state. The 'repo for-all git push' is still running and will take some time to complete, so if you sync now you'll get some parts with Gingerbread and some parts with ICS.
You probably don't. The AOSP is hundreds of individual git repositories. android.kernel.org and the "repo" tool are the only sane way to deal with them.
Special tools in the sense of "shell prompt" and "text editor" you mean? I don't disagree that being able to browse a big source tree on the web is a good thing, and useful in many circumstances. But I continue to be depressed at the level of fear that command line tools elicit in modern developers.
You actually don't need repo to check out individual trees; git works fine. And repo is really easy, there are "paste this in" commands on the AOSP site, after which you never need to look at it again if you don't want to (just git pull individual trees).
there used to be a gitweb running when aosp was hosted at kernel.org. when the repositories were moved to google servers, jbq@ said that a web interface to the repositories will be coming at some point, but it is a lower priority than other things like a gerrit review tool.