Kicad Arduino Schematics?
Correct. In that case, you want the signal from the socket header to driver stronger than the signal from the USB controller, which will always drive its Tx line. If you don't connect this signal to the outside, the resistor is unnecessary. There is no such resistor in the other direction, because the Arduino port is fully controllable.
One large cap (10u or more), and one small per-chip cap (100n) directly next to it is what I would do.


You also need something on the USB side (most likely, DTR connected to RESET through a 100n cap) so you can trigger a reset for programming.