- You don't have the ability to put a heatsink on your 6V voltage regulator, which may or may not be required (certainly required if you're expecting ~2A at 6V for servos! Unless you're actually using a switchmode BEC or similar.)
- Your traces and vias are very small. While it's somewhat controversial, I like to use larger traces whenever possible, if only for physical robustness.
- Similarly, you have traces that are very close together, or very close to vias. I am especially concerned about the (lack of) space between the mounting holes (GND) and the 6V power trace.
- 330 ohms as a current limiting resistor for modern LEDs is quite small, unless you want them as bright as possible. I use 1k resistors on most of my boards, and it's plenty bright for indicators.
- I would put extra pads connected to each of your "unused" pins, to make it easier to add functionality later.