I use a bigger but similar Behringer mixer, and it's great, no complaints there at all. A potential concern about a minimalistic one like that is that if you decide to add hosts to the podcast there's limited mic inputs, so it's not exactly future-proof in terms of where your podcast might go.
I haven't done much testing on this myself, but I've heard that a potential issue with bringing your audio in over USB (and maybe Firewire, not sure about that) is that since there's also power running along the line, it creates a bit of a buzz in your recording. I use a simple cable to go from the CD\Tape output on the mixer to the mic in on my computer; USB\Firewire is only really worthwhile I reckon if your computer doesn't actually have a mic in. A chunk of the price of that kit is that interface and it might not be necessary and may even be detrimental.
I would assume the headphones and mic are great for your purposes.
I don't think the software provides anything you don't already have or can easily download.
I have no reason not to assume it's a good kit, but you might be able to tailor things better to your needs by selecting the components you need individually. This pack is a good template to work from. Especially if you're planning on having more than one person talking, I'd recommend taking a look a few steps up in the Behringer Xenyx or similar lines, especially for a few more XLR (big mic cable) inputs.
Best of luck!
Shane