The Atmega328 probably won’t run reliably at 16MHz with only 3.3V, you need 5V for that. But you seem to be using the internal oscillator, so it will be 1MHz or 8MHz anyway.
What do you mean by Pin 0? Arduino digital pin 0? INT will need to be connected to a digital pin also, for the NRF libraries to work, I seem to remember.
Yes, that should work. Not sure about that led on the SCK line. What it it for?
What values are you using for R1 - R8? If these are not high enough, you will overload pins 23-26 (whichever those are). Remember max current from any pin should be 40mA, but lower would be better for reliability. You may need to put 4 transistors in there.
1, yes, it’s running at 8mhz ( will there be problems uisng nrf24l01 @ 8mhz?)
2, yes, pin0 means digital pin0
3, sck is pin 13. most boards have a led on pin13.
4, R1-R8 are 1k. don’t worry about that.