Citing academic papers in Wikipedia

There is a download available for all pages in the article namespace of the English language wikipedia which is located at:

http://dumps.wikimedia.org/enwiki/latest/enwiki-latest-all-titles-in-ns0.gz

However they do not generate this kind of list for every language, so you need to create it yourself from the all content dump. See the full list of all available dumps (just change the en-part of the URL to the language you want to see).

Yes, it is possible, but not directly on Wikipedia itself. You would need to use Pywikipedia for this.

There is a script in Pywikipedia called category.py. Lets say "foo" is the original category and "bar" is the category you want to merge into. Use the following command:

python category.py move -from:"foo" -to:"bar"

This would move all the pages in the "foo" category to the "bar" category. So, if you have multiple categories to merge, you would have to run this script multiple times for all the categories you have.