Elecrow is very good about telling you were you messed up.
But basically you want to setup a reasonable clearances .20 mm minimum trace and clearance will put you near the 8mils range they specify. That is what they recommend on elecrow and before you produce the gerbers you want to hit the DRC button to make sure you didn't miss something.
If i recall correctly kicads defualt setup is .251mm so it shoudl be good out of the box.
Also the silkscreen text is always smaller than you think it is make it larger as you can:)