I play a similar format so I feel I can assess fairly.
The first 3 rbs you took are all potential homeruns. Wouldnt be too shocked if all three ended up top 5 given their talent and the thought of three of your RBs turning in 150+ yard efforts any given week would scare the jesus out of me if you were my opponent. Your other positions are nearly as stacked, I love Rivers at value and Celek is a top 6 TE IMO. Your supporting positions of K and DEF are also very strong.
That said, your receivers are lacking. I'm not on board with Brandon Marshall. He went from two pass-happy coaches (Shanahan and McDaniels) to a running coach (Sporano). Miami has an identity and while they may open up the passing attack a bit, I find it hard to believe Brandon Marshall will pass 100+ reception again this season. Considering that BMarsh had over 100+ catches, he only had maybe 100 more yards than Ochocinco and just 1 more touchdown... yet goes two full rounds ahead of Ocho. Additional causes for concern include an awfully tough schedule and a very talented defense which should give little reason for the Fins to throw. Lastly, BMarsh is known for being a knuckle-head, you have to question his motivation after signing the second biggest WR contract in the NFL (only second to AJ) and coming off of a hip surgery. Still, there's no denying his talent.
I have my doubts with Driver and Santana Moss as well. Driver is clearly tapping his ceiling and its a long way down if his knees or fountain of youth dont hold up. Santana is very underwhelming, even if you add DMAC (who has lacks the accuracy to fully utilize Santana) and the Shanahans. Those two WRs are fringe WR3s in most leagues.
At this point, I would drop Anthony Dixon for a high upside receiver. In a half point per reception league, you can mask a lack of talent with high utilization. The receivers that come to mind are Jabar Gaffney and Mike Williams (TB). If those options arent available to you, I would try and trade up by offering a package of Donald Driver or Santana Moss + Brandon Jacobs for a player like Dwayne Bowe and change.
Bowe should flirt with 85-90 rec under Weis's pass happy offense and hes relatively undervalued.
QB: Phillip Rivers
WR: Brandon Marshall
WR: Dwayne Bowe
RB: Chris Johnson
RB: DeAngelo Williams
TE: Brent Celek
W/R: Jahvid Best
K: Nate Kaeding
DEF: SF 49ersviewtopic.php?t=470690