Using EasyEDA I've designed a standalone Arduino nano and plan to have a small PCB manufactured by jlcpcb. I've used the Nano's user manual as a reference for the PCB; within this scope I've used the same microcontroller (ATMEGA168-20AU) and kept close to the original design.
The circuit is modestly basic and will use a blank target ATMEGA168 placed by jlcpcb, which will have an Arduino sketch uploaded to it - my questions are*
 Can the ICSP be used for flashing the bootloader and then uploading the sketch with no extra wiring?
 Can an external Arduino flash the bootloader and then upload the sketch? (or is specialist equipment needed if these actions are done over ICSP)
 For a blank target microcontroller to recognise a sketch I understand the bootloader must be flashed first?
 Is the circuit schematic sufficient to work within the above context? So it'll be a basic PCB, bootloader flashed and sketch uploaded once only (hopefully if sketch is found to be stable)
*I'm sure it the answers are y in each question, I'm looking for confirmation before I press the order button on jlcpcb