Board Thread:Support Requests - Getting Technical/@comment-5530212-20150415125312/@comment-26009167-20150415141311

In relation to the first two questions, you may be interested in mw:Help:Extension:ParserFunctions, in particular the sections about #expr (for your first question) and #if (for your second question). It may be better for you to read over those two sections and try them out yourself. Remember, the preview button is your friend if you're testing them out.

In relation to the third question, you'll have to remove all the pages from the category. You can use a script like MassCategorization (from the dev wiki) to do the process for you.