You can't compare this to Jordan Reed. Reed literally risks further brain injury if he continues to play. It's ironic that you used that as an analogy, since even with Jordan Reed, the NFL isn't blocking him from attempting to play. They should. It's literally criminal that they aren't. But he's still out there. The only thing Alex Smith risks is breaking that leg again. Not being his surgeon/MD, it's impossible to know if that's more or less likely. Like I mentioned previously, despite the horrible nature of his injury (the spiral fracture alone was bad enough, but the fact that it was a compound fracture, and all the issues that resulted - just terrible), his repaired bone may end up stronger than it was before with all that titanium in place. There would be no basis to medically bar him from playing if the leg passes a physical. Him not being able to be the same QB because he's not as mobile would not be a reason to prohibit him from playing.
I don't give agents as much credit as you do. But ultimately I think the agent is going to do whatever his client wants him to do.
I don't know Smith or his wife, so that dynamic is hard to have an opinion on. But most wives are going to 'support their husband' when push comes to shove.
I really think it comes down to - is that leg fully healed and strong enough that can he get back to being able to play at a high level?
Like I said, I hope your right bud. I just don't see it in the way that my mind works. Maybe I just can't wrap my brain around the idea that the leg ever is healthy enough, and that's making my try to punch holes in that idea... but man it would be arguably the greatest comeback in the history of sports.