[calculate] rgb leds + sparkfun spi PCB + Arduino

[system]

1. 32 mil is enough for <1A, it also depends on the copper thickness of your PCB board.

2. Connecting the two GNDs anywhere should be fine

3. DRC is just for reference, you better check again to avoid some logic mistakes.

You might enjoy some time on this tutorial:http://alternatezone.com/electronics/files/PCBDesignTutorialRevA.pdf

Bon courage!