You can wash as often as you like. Actually I recommend washing everyday, because the more you wash the more loose hairs will come out of the braid and turn into knots. You should palm roll and wax after every washing but make sure your hair is dry before waxing because if you don't you will get a mildew smell.

While your dreads are new you will probably want to wear a swim cap, but after they mature you will not need one.

Yes, actually your hair will dread easier because the hair has been damaged, so it will hold knots a lot easier. You can use any method and the dreads will lock up.

You can ponytail, pigtail, or braid them. You can wrap them in hemp, ribbons, and string. You can dye them different colors. Wear a tam, crown, headband, bandana, toque, or those head wraps. You can put beads, peyote stitches, or Pyrex in too.