OP has only been here a month? Most of the experienced owners on here build their rosters by putting players in the best position to make an impact. All of the cases mentioned in the first post aren't uncommon in the game.
For instance, I'll take a FS and drop him to NB in the nickle and rotate another DB into the FS spot when I go with two deep safeties. And if that FS is my best KR, he'll be doing that too (although it's easier to find a 90+ SP and 90+ Kick Catch guy to do that and nothing else).
Most of us move TEs to WR (or, more rare, WR to TE) and move FBs to TE and move RBs to WR and then play the WRs as hybrid RBs and move QBs to RBs and the list goes on.
One of the best parts of roster building on this game is moving players to the spot where they can excel.