Exactly! Quest-Star Chart Decoupling is the solution. Make the quest menu similar to Destiny 2's "Timeline" chart where each quest's setting is briefly explained, and in between there would be summaries of major one-off events like Scarlet Spear and other "operations"... Then people can pick and play whatever they want from that menu.   As per item prerequisites: If you do not own a Necramech, Railjack, amp etc., you are gonna have to play with a generic one provided by the game