The flow direction aka flow of string energy direction, is basically what determines spin (still speculating here). Hypothetically, the strings contain photon 'joints' holding the string packets together and they loop around each branch in the specified direction. This looping also leads to stress points which cause a joint and string to imprint a behaviour to space-time. A branch is basically a single loop of energy from core to core, and the number of charged string loops determine electric charge strength. All fermions contain three branch loops, while bosons contain six. Or alternatively it could be that, fermions are odd numbered, bosons are even numbered in branches.
This you will have problems with if you take composite fermions into account. I assume you know about skyrmions (fermions made of bosons) and quantum field theory?
To answer your previous question first, yeah, the time axis is presented as linear with frames for now.
However, I'm not familiar with skyrmions and not too familiar with quasi-particles either, and I only know the very basics of quantum field theory. The truth is, I'm never good at gauging myself on how much I know something.