Congrads on your new crested geckos. I think you will quickly find out how awesome(an addicting) a CG can be.First thing I would do is join a more forum geared more toward Geckos.Personally I would recommend http://www.forums.repashy.com/ since it is geared toward Rhacodactylus geckos.There are many friendly and informative people over there that would be willing to answer any and all of your questions.
As for your questions.
1.All geckos grow at diffrent rates.This depends on a few factors such as Temp,diet and genetics but to give you a rough estimate. 3months
2.Pattern and color can develop as a gecko matures.Looking at it right now I would call it a fire/flame but I'm guessing as it ages it will develop more pattern on its sides and limbs and turn out to be a Harliquin
3.Once again this would depend on 3 factors Temp,diet,and genetics.This being said you gecko could easily become mature within 18-24 months.
4.I would say around 8 months
5.I would provide a water dish similar to your food dish for drinking water in addition to regular misting.You want mist enough to provide additional humidity but allow enough time for the enclosure to dry up so you don't promote mold growth.
6.The dish looks fine assuming the glitter is glazed into the pottery.I would however not provide mealworms but crickets or Dubias.People have even had success with phoenix Worms.
Good luck!