A theory on Heimdall...

So here it goes, this theory stems from a sort of common set of abilities three characters seem to have - Thanos, Heimdall and Red Skull.

On Vormir, Red Skull knew of Thanos' and Gamora's identity before they had introduced themselves to the Stonekeeper. This is presumably a result of being around the Soul Stone for ~70 years, since there are no possible ways for Red Skull to gain this omniscient knowledge over other beings (after all, he was cursed to guard the stone and guide those in search of the stone, so he couldn't possible leave the stone or Vormir).

This brings me to Thanos, who seems to know of Tony Stark after gaining the Soul Stone. The Soul Stone appears to give the wielder (or those in very long exposure to it) the knowledge of all living beings in the universe.

Now, Heimdall has claimed to be able to see 10 trillion souls from the observatory at the end of the Bifröst Bridge in Asgard. We know that not all guardians of the bridge are able to have this power, since Skurge needs an intergalactic pager (don't know what that flashing/beeping device in the middle of the observatory in Thor: Ragnarok was called) in order for Thor to signal that he needs transport.

So what I'm saying is: Could Heimdall be a previous stonekeeper on Vormir?

Red Skull has only been the Stonekeeper since 1945, and ~70 years is not much time for an Asgardian. It is possible that Heimdall was once a villain that sought for the Soul Stone (that would explain his line about dark magic), and he was then cursed in the same way Red Skull is/was. It would've been possible for a powerful being like Odin to break Heimdall of his curse, and then employ him as a gatekeeper (considering his previous experience in being a guard).

What are your thoughts on this theory?