I agree with much of your take.
Here is where I see it somewhat differently.
I would say that the Rams have no VETERAN depth on the oline. You (I think) mentioned that the Rams might look at the waiver wire on cut down day for this. I agree. But I don't think the Rams have no depth as you do. We've not see Donnal play because he's been injured. I think Williams has done far better than being given credit for . Blythe has had one bad outing and one good one. Eldrencamp has impressed me.
I don't see the right side as problematic at all. People keep knocking it, but when I watch every play in slomo I just don't see it. They have done just fine and against the Raiders they were better than against the Boys. The right side seems to be getting measured by one missed assignment by Brown that got Gurley clobbered behind the line. And the very visible sack of Goff by Mack that had everyone slapping their forehead had nothing to do with oline; it was on Everett and Higbee.
About the only reason that they may not be a good road team is youth. Otherwise I don't know why they'd be a bad road team. In the NFL pretty much all teams do better home than away. However they beat the Raiders in an away game. I just can't speculate much because to me until they begin the season there is simply no way to know.
I think they are fine with Mannion as a back-up. He's run the offense efficiently using mostly 2nd teamers. All teams have a drop off to the 2nd string QB.
Goff looks wholly different from last year. If preseason play is any proof. they ARE improved at QB; but how much? We'll see. Some of that "improvement" is simply having better oline blocking, WRs that can get open and catch the ball, a RB that can be consistent (Gurley has not impressed me in a very long time), and good schemes and coaching. QBs don't operate in a vacuum. You don't get brilliant QBing on bad offenses.
I'm not even sure that Joyner is our best FS. I've not been impressed so far. The guy who has played the best so far is Cody Davis. And I really don't like it that Joyner seems to lose his cool so easily. Frankly, I'm pretty surprised at all this. I thought Joyner would tear it up at FS.
As for McVay: everything will be new to him from his perspective as HC. So he's going to make mistakes. But it won't be from pressure. To me, this is the year to make the mistakes. 2017 is going to be the learning year across the board. Learning to play a new D. Learning to play a new O. Goff finally learning how to play NFL QB (he learned NOTHING last year except maybe how fast the game is and how important an oline is). And the Rams finding out who fits the schemes they have put in place and who doesn't.
