He will line up out wide in 3 WR sets, not that hard to understand and no not every 3 wide play will have him out wide and he's obviously not the check down option on every play lol.
Really depends on the position, like RB yeah sure that position can rotate a lot especially if you have a bunch of solid but not super talented RBs.
But some positions you just do not rotate (O-line, QB, CB etc.)
If the NFL was rigged you wouldn't hear about from conspiracy nutjobs, you'd hear it from refs, former officials etc. It would basically be the WWE but it's not because you cannot fake incompetence like the NFL does.