Seeking education on fuel pumps, gas caps, vapor canister

[71CHEVYSHORTBED402]

71 c-10 402: I plan to install the charcoal canister with the rebuild. The aim is a stock set-up. A lot of questions, sorry about that. Appreciate any input.

1. Know which is the inlet from the tank to the fuel pump, #1 or #2 in the image?

2. I read one of these is a return line, "for cooling". Is that true? They also said this set-up requires a vented gas cap. Sounds like a vapor canister set-up, but what do I know.

3. I thought the other line was due to not having the vapor canister active. Is that a different line?

4. Did the original fuel pump have just one line from the tank?

5. With the canister installed, do you recommend I use a vented gas cap or not? Seems not, but.......