Most bang for buck when turning in Challenges and bounties?

[random river]

i am trying to level up my seasonal artifact, should i turn in my seasonal challenges now or should i wait for a fireteam member to get combined wisdom, or wait til reset etc

anything i should do to maximize my xp gain?

[sweet quartz]

start of the week for 2x xp, max bonus shared wisdom, 12% xp ghost mod

[random river]

isnt the start of the week bonus only for 3 season pass levels? and how do i get max bonus shared wisdom

[sweet quartz]

5 levels i think and you can make it last for more if you turn in all the seasonal challenges quickly. and max shared wisdom requires 1 person who is high enough level to get the last bonus from the season pass