The kanji for "Gai" in Ikari's name isn't even the same as Condor's "Gai," so...I don't know why the Japanese fans even thought that was a plausible theory.
As for my opinion on Gai Yuuki...c'mon, you know that type of character appeals to people. When I first watched Jetman, I was reminded of the X-Men love triangle -- Gai is the Wolverine to Ryu's square Cyclops. You know how everyone loves Wolverine...
I think a lot of what makes Gai work is the actor. Wakamatsu's a great actor and manages to make that character likable, even early on when Gai being a pain. I can easily see how annoying the character could be in the hands of a lesser performer -- Gai would be no different from any of Inoue's post-Agito prickheads, the difference is Wakamatsu.