I use echo oem black 3mmx6mm for fuel line and impulse line.
The echo oem black in 3mmx5mm can be used for fuel line too. Which I have in past. I just like the bigger for seal going through.
3mmx6mm for impulse line for sure.
Tank vent on side of tank. Prone to coming out too. Not a line but a duckbill and sinter brass piece.