1) sellPrice 2.0 means sell 100 metal or crystal for 200 credits
buyPrice 4.0 means buy 100 metal or crystal for 400 credits
vary the values to suit
2) priceIncreaseAtMaxShift 2.22 = factor by which the price of selling/buying both metal and crystal change
minTimeForMarketChange 10.0 if you want to make this predictable make the min and max values
maxTimeForMarketChange 30.0 the same
change values to suit
4) minLengthOfCrashOrBoom 20.0 if you want to make this last longer change the values to be the same
maxLengthOfCrashOrBoom 200.0 and larger
As for 3) and 5) Not sure how to do those. Hope this helps you though.