What we've found for the motorised JM44, is to drop roller down, until the rise/fall wheels go slack (so the top roller is resting on the substrate), then back off by a quarter/eighth turn.
Cut a piece of board 2-3" deep, by the width of the adhesive, and apply that through the laminator first, as a leader board. then pull it back to the reverse of the nip (i.e. so it at the exit of the rollers). Then you have a better chance of loading the substrate parallel to the nip.
On the motorised rollers, we keep a moderate tension (fingertip braking) on the feed roll, to avoid "bagging", which is one of the ways of making waves and bubbles. The good thing about using a self-wound adhesive, is that you get to re-use the leader boards, as they already have a silicon release layer on top.
For the sake of sanity, perhaps cut some longer 8-12" leader boards, to confirm that you've got parallel loading sussed.
Also, be aware that when you've cut the board from the roll, any adhesive which has left the feed roll is likely to only be good for loading onto leader boards (i.e. its wasted for mounting purposes).
Good luck - two out of three aint bad.