User blog comment:Spongebob456/Bot help/@comment-26686429-20130119175033

TK's advice is good, but here are the answers to your questions:
 * No, you don't - but you need staff approval to give it a bot flag, which means edits don't show up for people monitoring changes on Recent Changes. You should also ask your community to see if they're ok with you performing automated tasks using a bot.
 * 1) It depends what you mean by complex, and also what you want to do with the bot. Software such as Pywikipediabot and AutoWikiBrowser has been written to automate tasks that most people want to do. If you want to do something more advanced, you'll probably need to write some code to do that, but pywikipediabot offers a framework for that, so you probably don't need to start from scratch.
 * 2) A bot can be used to perform automated tasks on a wiki. See my blog (linked by TK) for examples on what you can do. The way to approach it is not "I have a bot, what can I do with it" - but "this task looks like I'm going to be doing the same thing over and over, a bot would work well for this"