Mostly disagree, poplar.
In fact, about the only thing I strongly agree with is the need for more depth. Lol.
First of all, I'll set the D and ST units aside for the purposes of this discussion. Both have demonstrated their respective abilities to more than hold their own in real games. Heaven only knows how well the D would look with just an average O helping them out, for example.
As to your litany of O personnel shortcomings? I want to see what these same players could do under the direction of a decent HC and his staff. Just DECENT. Is that too much to ask before we throw all those players overboard?
IOW, I suspect that our O struggles should be 80%, or more, laid at the feet of Fisher and his staff, rather than on 11 O players. Which makes more sense? All 11 of our O players suck and are in the bottom 2-3 in the league? Or the coaches aren't training and using them properly?
Our OL is a classic example. All 5 starters simultaneously take a step backward in '16? All 5? Or the coaches changed something in scheme, technique, or game planning that affected all 5 players?
It's an Occam's Razor thing, if you ask me.
Keep replacing players is not necessarily the solution. Keep the same crappy coaches and you're gonna keep getting the same crappy results.
Look no further than these guys:
Goff rides the pine for 9 games.
Gurley goes from OROY to 38th of 40 at RB.
GRob a #2 overall described as a freak at the time to getting benched in his 3rd season.
Quick took 4 years to start looking decent.
Tavon at #8 overall and still not used properly.
Hav went from an excellent rookie year to anonymity in one season.
Oh heck. Why go on? It's mostly on these coaches, man. They're a league laughingstock.