I am by no means an expert so others will add their own opinions. Thats the beauty of this forum. Everyone is very helpful. And welcome to the forums.
1. The baby gecko could live in that size enclosure up to 10-15 grams. The set up would take that long to ship, after receiving it you contact Pangea and they ship it to you overnight.
2. These temperatures are at the lower end of what Cresties should be kept at. Do not use a heat mat though, They produce too much heat.
3.It all depends on how much you give the little one each time but I would estimate somewhere around 6+ months.
4.They are addictive....