I am thinking of moving/reassigning FS Cory Vargas from FS to CB
Moving/reassigning C Carl Lawlor from C to LG
Moving/reassigning WLB Roderick Carver from WLB to MLB

Take a look at my team and give me your opinion

My weights for Vargas have his current/future ratings as FS 60/95, SS 49/95, CB 45/91. If you had 2 other decent CB's I would suggest keeping Vargas at safety until he grows into his ratings, like I did with this guy in MFN 73 https://mfn73.myfootballnow.com/player/4152. You don't, and Vargas is your fastest DB with 100 potential M2M, so stick him at CB. He will give up some plays at first but stick with him, as his ratings grow his catch allowed should shrink.

Man, I thought I had OL problems. I can't see your depth chart, but if I were running your team, my current starting OL would be LT Davidson, LG Lehman or Cormier, C Lawlor, RG Courtney, RT Martin.

I believe Martin is your current center, but by my weights he is a better tackle. Centers need intelligence and snapping ability moreso than G or T and Lawlor is 100 intelligence and your 2nd best overall short/long snapper behind Riley. Lawlor is already a better blocker than Riley, and should be your center for the next decade.

Courtney is the only RT I saw but with 100 run block and 52 pass block, he needs to be a guard. Cormier is close to Lehman in my guard ratings and a case could easily be made for him to start over Lehman. Cormier has better run blocking than pass, which is why I'd move him inside.

Concerning your linebackers, you want your best one at WLB but it really comes down to personal preference. Nothing says you can't move him around using overrides, in fact you should probably check your nickel/dime packages and make sure Carver is in there somewhere and not one of the other guys.