So what's your tower like when it gets near vertical, and the balance passes over center? In the video it seems only a bit of handling is required to bring it gently down by hand.
(Always interested in tower stuff, you know that).
As for the resistors, symmetry is pretty, but overall if the resistance is low enough to effectively limit speed, doesn't overload other components, and the resistors themselves can take the heat, then you've got it, whethe it's symmetrical or not. Long term reliability and ability to troubleshoot problems in the future do benefit from having balanced phases, so it's not all theoretical.