LaTeX.org

+1.
Sorry
+1

I think the LaTeX Companion is the one you should buy.

I'm facing the same problem with graphics produced with R and using mathematical expressions.

You will find a solution for your problem there http://www.latex-community.org/viewtopic.php?f=31&t=14

You can choose the language used for a project in Project, Spelling...
But there's seems to be a problem with this setting since it is not taken into account by TeXnicCenter. I face the same problem (use of french and english)

Yes. You have to install a soft called AREnable (you can find it on sourceforge) and use it as post processor in texniccenter

Yes, you just have to create a project with your tex file. However it won't list the references that are in a bib file. If think you should have a look at Jabref which is a powerful bib file manager.

Yes, I have the same feeling. I hope, this will be soon corrected