In the annals of Star Wars history, many believe Obi-Wan Kenobi was the key to saving Anakin Skywalker's soul before his fall as Darth Vader. However, as Kenobi's recent Disney+ series showed, that was never really the case. Anakin lost himself to the Dark Side way before Obi-Wan's intervention.
The most likely scenario involving survival would see a victim of such injuries put on life support and disabled, probably either bedridden or requiring a mobility aid of some kind, in addition to prosthetics and a respiratory aid.
While Obi-Wan and Ahsoka were each able to unmask a sliver of Anakin, only Luke is able to fully take off the whole mask at the end of Return of the Jedi.
According to George Lucas, no one could save Anakin once he started on that path. When he betrayed the Jedi and killed the Younglings, he was too far gone for Padme to draw him back. He had embraced the Dark side, felt it's power and believed it could give him what he wanted, to bring his idea of order to the galaxy.
Sadly the Clone Wars would have still happened, but Padmé would have also survived, giving birth to Luke and Leia who would have probably been inducted into the Jedi Order. As for what would have happened between the two, with their marriage and all, that's a bit tricky.
If so, then there would be a secret Padme would have to keep about who killed the twins' father. They would likely find out the truth and, given that they had the genes of Anakin, they wouldn't be too happy to learn that the Jedi Master who trained and helped raise them was actually the person who killed their father.
Anakin wasn't "too old" because children were more adept at learning the Force — he was too old because he already had attachments to the physical world. Thus, Anakin couldn't properly be indoctrinated like other Padawans because he had knowledge they didn't.
Anakin Skywalker, the Chosen One who brought balance to the Force, also spoke to Rey, urging her to follow in his footsteps by restoring the balance.
Anakin's tragic flaw was his fear. This was the reason the Jedi council restrained him from being a leader for the simple fact that he feared his wife Padme's death, the safety of his mentor, Obi Wan Kenobi, and he feared the safety of all the clone troopers placed under his command.
In the duel, Anakin lost both of his legs, his one remaining organic arm, and suffered (possibly up to) fourth-degree burns across what was left of his body that were severe enough to damage his internal organs.
A recent study found that Anakin Skywalker's turn to the dark side was the result of Borderline Personality Disorder (BPD).
Palpatine may still have eventually traded Dooku in for a newer apprentice, but nothing would have hindered his rise to power. Had Qui-Gon trained Anakin and kept him far from Palpatine, Anakin might have eventually died in the Clone Wars and been completely unable to fulfill any Chosen One prophecies.
While Force healing could have saved Padmé, material from both continuities explains why Anakin couldn't use it. The Force is a fundamental omnipresent energy that can be used as “powers” by those who are trained to tap into it. One such power is healing oneself or another at an enhanced speed.
Anakin's unhealthy link between his love and attachment is perfectly explained in Clone Wars: Overlords. He admits “The only love I feel in my heart is haunted by what would happen should (if) I let go.” Anakin is never happy, not even with Padmé, because he is constantly afraid what will happen to him if he loses her.
Yes. In the book 'Tatooine Ghost', Leia learns of Anakin's life prior to his evolution into the Darth Vader personae. This revelation leads her to forgive him. She even named her third child in memory of her father.
In Star Wars Legends Leia was visited by the force ghost of her father Anakin Skywalker, the man who used to be Darth Vader. It wasn't a pleasant meeting as Leia was unable to forgive him for the things he'd done no matter how hard he begged, and it was the only time she saw him.
In the darkest hour, Padmé Amidala became a Force Ghost. Padmé, knowing that her childern should be kept in hiding until the time was right, kept this new found ability a secret. As he heard of the news, the spirit of Anakin Skywalker in shock of what he did on Mustafar, disappeared forever into the Force.
Padmé was born in 46 BBY (Before the Battle of Yavin) and Anakin's miraculous Force-created birth came in 41 BBY, so Padmé is five years older than him.
In short: He felt Luke wasn't ready. Yoda was the grandmaster of the fallen prequel-era Jedi Order and trained Jedi for centuries, with students typically beginning as young children. He saw too much of Anakin in the young adult, and he didn't want to end up training the successor to Vader.
Anakin Skywalker
As Yoda considered such things to be dangerous, he thus deemed Anakin unfit for the life of a Jedi. Even after learning of Qui-Gon's death and Anakin's heroics during the Battle of Naboo, Yoda agreed to have Anakin join the Jedi Order but was against Anakin being made Obi-Wan's apprentice.
Yoda didn't specifically know how this would go down, or to what degree Anakin would cause it to happen, but he was playing a much longer game by Revenge of the Sith, and that's at least, in part, explained by Yoda's Force connection with Qui-Gon's spirit.
If Anakin went to Utapau with Obi-Wan, they would both defeat Grievous, Anakin wouldn't turn to the dark side, but Yoda and Mace would have to help him and Obi-Wan stop Palpatine. If Anakin avoids the dark side, he would still be with Padme and they would live together with Luke and Leia.
If he were to take his mask off, the Sith Lord would soon suffocate. So it's the most crucial part of his armor. He can only breathe without the need for his mask when he is in one of his meditation chambers seen in The Empire Strikes Back.