@Arhael
All of your three theories have some nice points. But they have bad points either.
I like this one:
The answer is rather obvious - superior power gives superior Force defences.
Or this one...
In film their direct TK contest was draw, which is very strange considering Anakin's superior power comined with rage level. Either Kenobi was driven beyond limits due to circumstances or Anakin simply wasn't, yet, very skilled with offensive TK.
My interpretation is similar. And i think, that Anakin and Obi-Wan - as a jedi - were better at defensive force powers. So maybe Anakin's offensive push was a little worse then Kenobi's defensive.
I've also agree with that:
By getting enraged he equaled Dooku in combat but couldn't overpower him, however, he utilized grappling technique which Dooku as pure fencer simply couldn't counter.
Unlike Dooku Kenobi apart from fencing is skilled unarmed combatant, so when it came to grappling Anakin couldn't win him.
Anyway, you should accepted just one fact: Kenobi was'nt as skilled swordsman as Dooku and Anakin.
He defeated Anakin not becouse of his superior skill, but becouse of his inteligence and calm. They (Anakin and Obi-Wan) perfectly knows each other, but Anakin's state of mind gives this advantage to Obi-Wan. Obi-Wan was also Soresu master, which maybe was the best form, to counter Anakin's powerful attacks.