Stormbreaker can be used by anyone, it isn't bound by Odin's enchantments to only be lifted by the worthy. Mjolnir is, however, still enchanted, meaning that only those that are worthy may wield it. This applies to your last two questions as well. If you can lift Mjolnir, you can wield it.
Can anyone lift Stormbreaker? Yes — and the reasons why a crucial point in the comparison between Stormbreaker vs Mjolnir with respect to Thor's character arc in the MCU. The God of Thunder went through a massive transformation in Taika Waititi's Thor: Ragnarok, which continued into Thor: Love and Thunder.
Stormbreaker does not require its wielder to be “worthy” - as explained by Thor in Infinity War, anyone can wield Stormbreaker as long as they are strong enough.
Can Thanos lift Mjolnir and Stormbreaker? He's able to hold Stormbreaker because it does not have the “He who is worthy” enchantment on it like Mjolnir did. If you recall Mjolnir did not have it either until Odin places the enchantment on it when he banished Thor at the beginning of his film.
Following Mjølnir's destruction, the weapon was forged by Thor in order to defeat Thanos. After Mjølnir's reassembly, Thor allowed his adoptive daughter Love to wield Stormbreaker in combat.
Thor's hammer Mjolnir was defined by the fact that only the 'worthy' could lift it – so basically no-one except the god of thunder (and Vision, for some reason). But when it comes to the weapon's replacement, Stormbreaker – which Thor forges in Avengers: Infinity War – Groot is able to lift it too.
Originally Answered: Can Cap and Iron Man lift Stormbreaker now? Yes. Anyone can lift storm breaker. Because Odin did not said that Storm breaker can only be lifted by those who are worthy as he has said to Mjolnir.
Stormbreaker has the additional power to summon the Bifröst, allowing Thor to teleport anywhere in the Nine Realms. Screen Rant has identified Stormbreaker as the more powerful of the two, based on this ability, as well as it being a much larger and edged weapon.
It is safe to say that Stormbreaker cannot be destroyed by anything audiences have seen in the MCU so far. A power that Stormbreaker lacks is the "worthiness" enchantment of Odin. Anyone physically strong enough to lift and use Stormbreaker can use it.
In AVENGERS & X-MEN: AXIS (2014) #9, Loki found himself in the unfamiliar role as the hero when he confronted the inverted “evil” Thor on the moon. This version of Loki was so pure of heart that he was able to pick up Mjolnir and transform into a version of Thor.
As there is no enchantment upon Stormbreaker, anyone can lift it, however lifting it is different from being able to wield it. Unlike Mjolnir, Stormbreaker will not bestow the power of Thor upon whomever lifts it. Essential the most anyone would be able to do with it is use it as the battle axe it is modeled after.
He traveled to Nidavellir and forged Stormbreaker, a weapon not only strong enough to kill Thanos but counter the Infinity Gauntlet and even summon the Bifrost. However, the weapon wasn't ready until Groot completed it by dismembering himself - and, in doing so, he became the first person to lift Stormbreaker.
MCU Thor cannot fly without Stormbreaker or Mjolnir. The best he can do is jump long distances, which is still dang impressive. Stormbreaker is called the King's weapon in Infinity War.
There's a chance it could be repaired -- after all, Mjolnir has been broken and remade on multiple occasions -- but seeing Thor break Stormbreaker willingly is still a shocking sight. By destroying Stormbreaker, Thor not only reaffirms how powerful he is, but he also shows Bill how determined he is in his new quest.
Thor. Thor, the god of Thunder, was undoubtedly the most powerful member of the original Avengers. His power continues to grow in the Marvel Cinematic Universe.
Why can the bad guy pick up Stormbreaker? Because unlike mjolnir, Stormbreaker doesn't have any Magical-enchantment on it. It's just heavy and can be lifted by anyone who's physically strong. It doesn't have any special worthy enchantment on it.
The hammer Stormbreaker is very similar to Mjolnir, made of mystic Uru metal and is nearly indestructible. Worthiness: Just like the original Mjolnir, no one can lift Stormbreaker who is not worthy. After the founding of New Korbin, there was a line of aliens and Korbinites all attempting to lift Stormbreaker.
Overall, though, Stormbreaker seems to have the edge over Mjolnir once again. Strong enough to open the Bifrost, reach Eternity, and manipulate storms the same way Mjolnir can, Stormbreaker's powers are greater than that of the mythical hammer.
So, while Stormbreaker grows roots in Thor: Love and Thunder, it is not another Groot being grown but an extension of a plant with the feelings of a teenager. Stormbreaker's jealousy comes from being born of a teenage Groot, and that's why it's so anthropomorphized in the film.
He has feats such as defeating Surtur (who can destroy a planet), conquering the 9 realms, and sealing away Hela. While there isn't much doubt that Thanos could beat Odin if he had all 6 stones, Odin could probably defeat Thanos if he only had one or two of them.
Rune King Thor is perhaps the strongest version of Thor we have ever witnessed in the Marvel Comics. In the desperate need of power, Thor makes the ultimate sacrifice of his life in the Mighty Thor #80–85. He hangs himself from the tree of Yggdrasil to get his hands on Rune Magic and he literally died.
Mjolnir doesn't damage Cap's shield at all, as shown below. I think it is fairly safe to assume that Stormbreaker (being a cutting weapon, rather than Mjolnir which is designed to smash or build) would inflict similar damage to the shield as Thanos sword does. Conclusion: Stormbreaker minces Cap's shield.
Clearly, Thanos is aware he wouldn't be able to lift it. Although it's hard to pinpoint what exactly makes someone worthy of using Mjolnir, as it's ultimately determined by Odin, who placed the enchantment on the hammer, some believe one's worthiness is measured by traits like courage, honor, and selflessness.
Following the line of one's self-concept and limiting beliefs being what keeps people from being worthy of Mjolnir, then Tony would have never been worthy, as he never fully overcame his deepest fears and most of all his sense of unworthiness.
The answer is that Thor can't beat Superman with his Stormbreaker, of course, his Stormbreaker will provide him extra power and capabilities but winning against Superman is not possible with that Axe. But it can harm Superman because the axe is enchanted and Superman is vulnerable to magic.
