Phil's back story is quite interesting. He started out with a passion for justice and worked hard to gain the skills and knowledge needed to be part of the Avengers' support team. Along the way, he had to overcome various obstacles and make tough choices.
The 'Time Runs Out' storyline in the comics is relevant. It deals with time - travel and alternate timelines concepts which are key elements in Endgame. It gives an idea of how messing with time can have far - reaching consequences and sets the stage for the Avengers' time - heist in Endgame.
Well, the back story of Avengers Infinity War is complex. Thanos has seen the chaos that overpopulation can cause as his own home planet Titan was destroyed because of it. He believes that by getting all the Infinity Stones and using their power to snap his fingers and eliminate half of all living beings in the universe, he can save it from the same fate. The Avengers, on the other hand, have been formed over time to protect the Earth and the universe from various threats, not realizing the full extent of Thanos' plan until it was almost too late.
Well, Iron Man's back story involves him being a genius billionaire playboy philanthropist. He was captured and built the first Iron Man suit to escape. Captain America was a small, sickly guy named Steve Rogers who got chosen for an experiment that turned him into a super - soldier. Thor is from Asgard, a god who was banished to Earth and had to learn humility here.
One great comic to start with is 'The Infinity Gauntlet'. It directly involves Thanos' quest for the Infinity Stones, which is central to the Infinity War story. In this comic, we see how powerful the gauntlet is when all the stones are assembled, and it gives a clear picture of Thanos' motives and capabilities.
Sure, the Avengers do come back in the comics. Their comebacks are usually tied to complex story arcs and character developments. It's all part of the ever-evolving world of comic book storytelling.
I don't know for sure. Maybe you can follow some comic insiders or fan communities on social media to get the latest rumors and speculation about the return of the Young Avengers comics in 2018.