The world is now tuning away from regular AM/FM radio and to XM radio and Podcasts in droves.  People want to hear what they want to hear, i.e. what's of interest to them.  You need to start a podcast to build your audience with the people already interested in your topic.  You may even create some customers in the process.

Recording and editing take most of the time, and then there's the process of promoting which can also take some time.  The goal is to get it on a calendar and manage the time required until it becomes habit.

Sure, as long as you have a passion you want to share with the world.  I say, go for it while you're hot about it, and people will come closer to you.

Linke anything else, when you're paying for a service, you recognize you must actually do the work.  There's work involved in creating a podcast, even if all you have to do is show up and talk.  You should still prepare an outline for every episode so you have a goal you want to reach for your audience. 

Not right now.