I know you appear to have cured the prob, its hard to tell from the last video, as the heli is spooling up, but I think you have the flybar link on the wrong side. People may say it makes no difference, but believe me it does! It should "lead" the blades, not "trail", which I think your is doing. Even if all is ok, take the flybar off, swop it over, so the link is on the other side, and see what happens, if worse, I am wrong looking at your video, if better, pass on the good news!.
I upgraded to xtreme, and whilst I no longer break blades, its much harder to set up, mine are just a bit too sloppy for my liking. THe flybar mod worked for me, and stopped that horrible "swaying" motion that you sometimes get