First question: No, you don't need a tablet to make things work. Most of my early work was done without a tablet, and there are some fantastic artists who are able to do magic with a mouse. However, in my opinion, a tablet makes drawing and coloring on a computer MUCH MUCH EASIER. But it's not necessary, and if you don't have the ~80$ to blow on one, dont' worry too much about it.

Second: If you're talking about drawing a character front-view or something, and then being able to tell the computer to make it into a side view or a rear view of the same character, unless you're working in a 3D rendering program it can't do it.

Third: Panels will go in any order that you tell them to go in. In the few comics I've done, I've drawn out every panel in my sketchbook, scanned them into my computer, then made boxes in a page-size in GIMP (I like to work in 5x7 now, but sometimes I would do 8x10 or something like that) and inserted my scanned drawings into the boxes, erasing outside the boxes to make it clean (or erasing the boxes and let the image go full-bleed.

And last: I've done little GIF animations in GIMP, stuff similar to flash animations and such. I'm not sure if I ever used the built-in animation thing in GIMP, though - if my memory serves right, it was typically a way to convert an image into a spinning globe or something to that effect. If you're looking to do animations, you'll either have to do it the old-fashioned way (drawing out the frames, ~8 frames per second for saturday-morning cartoon quality) or get and learn Flash.

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I like blue.