New bearded dragon owner

Question
I have researched on bearded dragons alot but im still wondering on some questions 1)is it true the cricket u feed the dragon needs 2 be smaller than the space within in eyes 2)whats the smallest tank size for a 2 year old male dragon 3) what greens do they eat 4)Is washed playsand the best sand for a bearded dragon 5) whats the temp in the tank for the 2 year old dragon 6)should the tank have alot of things inside the tank
                                   
                                       Thanks Frank

Answer
1) True
2) 40 gallon breeder tank
3) Collards, turnip greens, mustard greens, dandelions, mache, arugula
4)washed, sifted childrens playsand is the best sand, but the best combo is half carpet with a sand area to dig in.  The carpet area for eating his salad.
5)Basking side should be 100-105F, 70F on the cool side, measured with a digital thermometer.
6) A few things to climb, a cave or log to hide in is nice