While I agree with most of the OP, I'm with Kearly on this one. I'd like to see us draft a WR to upgrade the 3rd-5th spots. Our depth is bad, and I agree with you Montana about if Tate or Rice gets hurt we're screwed.
Thing is, both teams have grown, and both teams have changed....it makes an intriguing matchup.
We did not run the read option at all in our first matchup. Wilson makes the read option so tough to defend because he actually throws the ball well, unlike most the read option guys in the NFL (exception RGII). If the DB's stay back, Wilson or Lynch will have room. If the DB's come up, we're going to see Miller and McCoy eat their lunch.
McCoy has grown this season. I think he'll show up this game, and is fast enough to get separation from SF's LBers. Turbin's big drop in that first game was more of a rookie thing in a big game, not being intimidated by anyone. He's also gotten better.
The biggest worry I have for this game is the defense crapping the bed. I think fatigue played a big factor in that first game, in the 2nd half of the game during a short week. SF ran all over us in the 2nd half. I also worry about our fill in guys (Lane % Maxwell) stepping up to play well in a playoff atmosphere. I think Thurmond will be fine; SF's WRs don't worry me at all. If we can stop their run, spy Kaepernick, and stop Davis, we win easily. It's easier said than done.
SF barely beat us during a stretch where our offense was anemic. We're running the ball well again, incorporating the read option, and our TE's and WR's have grown as a unit. Wilson is seeing the TE open more, McCoy is developing a good game, Tate has grown into a big threat WR, and Rice is reclaiming his #1 WR status, with also taking some brutal hits and staying on the field.