How can I create animations (gif) (flash) using inkscape? How do I add sound to those animations? Apparently there is a way by downloading swftools but which swftools do I download (because there are so many!) and where do I download it? Please explain simply in a step by step way. OR do you recommend just buying xara xtreme because they can do those things naturally as part of their program?

swftools do I download (because there are so many!) and where do I download it? Please explain simply in a step by step way. OR do you recommend just buying xara xtreme because they can do those things naturally as part of their program?

I've used Xara's animation tools before and they are pretty nice. On the other hand, before you make any decisions, check out Synfig (http://www.synfig.org). Might be what you're looking for.

You can also use Blender!
Just cause it was designed for 3D, there's no reason you can't use it for 3D animation.