Maybe the stem is too long for the crown? Did you try if the crown screws in completely when you try without movement? If it does, you need to cut the stem a little bit. Sometimes the crown is not compatible wit the crown tube, it starts screwing in and then stops. That would be bad. You can cut a stem which is too long, but if the crown tube is not compatible with the crown, you have to replace one of the two.
The dial: it is more straightforward to glue the dial to the rmovement ring, or, if not present, to the movement directly. Use very fine drops of 5 minutes epoxy, maybe four of them, thats enough. You have then approx. Five minutes to move and align the movement before the epoxy settles. Take care to carefully clean and sand the areas where you put the glue, especially on the movement. I am using GC metal primer, but thats very expensive and not available to everybody. But befor doing this, check thoroughly that there will remain enough clearance for the datewheel with the overlay to move freely.
Another option is to use dial feet, you can use those which came off your gen. dial, screw them into the movement in a slightly protruded position, so that they stick out (only a little bit). It is important that the end is flat, if no, grind or sand it nicely flat. Then apply the 5 minutes epoxy to the pins, place the dial on the movement and let the glue settle,then loosen the screws and push the dial tight on the movement and fix it with the screws. Sounds challenging, but is really simple.
dont give up, take your time, it is very rewarding to wear a self-built franken with gen. case and dial.