I didn't mean to sound harsh (I tend to generalize what I see), but I essentially agree with most everything you posted. Kid is out of place in this system so to me it remains to be seen if his attitude and drive make up for that.
I'm not saying we need to get rid of him, at worst he's a prime candidate for a position change if it comes to that.
I don't have the opportunity to watch practice, so I'll clarify by what I meant as "two springs". When Riley rolled in, he had the same amount of practices as TA, Fyfe and all the other guys to establish himself as a (at least then) viable backup. Fyfe beat him out, which is not at all odd for their age disparity/experience disparity.
Then this year, more talk of unlimited ceiling, but extremely early in the cycle, Riley comes out and basically "cements" in a 1-2 of TA/Fyfe barring some radical fall one lay fan would assume. I assume Riley doesn't come out to the media that early unless in his mind, the trajectories don't seem radically likely to change.
Bush may be the most improved player on the team, but if he's essentially QB3 2 cycles after he started as essentially QB3, there's at least a modicum of spinning one's wheels there, especially when most fans realize QB2 is not exactly lighting the world on fire. And lets remember, Bush has had the playbook the same amount of time as the other QB's on the roster, its not like Fyfe got 2 years advance warning of the new system.
And all the while, talent that fits this system keeps stockpiling in front of him. I'd love nothing more than for Bush to come out and be Michael Bishop in terms of production, but if I had to push my chips into any sort of pile, it probably wouldn't be his.