I have a very similar prop on our Johnson bombardier 4 blade stiletto II...
Absolute magic economical , good cruise, maneuverable prop..
The Johnson has 2 methods of locking the nut....not sure which that model of bombardier has..
1/ like a axle nut on a car or trailer wheel....spacer/ thrust washer on at rear, that fits on a machined shoulder.... then the prop, then a washer that fits in the spline, then the castle nut, torqued up to remove all end play (not centrifical play as per video) then split pin
2/ Same as above, thrust washer, prop, washer lock washer nut as u have... these are torqued up with a block of wood between the cavitation plate and prop...
If either of these are loose, they sit on machined splines, there should be no play on the splines... which means tighten up the nut more will not make any difference
I have replaced my prop so many times...I cant actually rem if there is any centifical movement... and is currently in the workshop for full annual service.
Thats does seem a lot thu....Any play like that will be in the setup of the gear gear box... like setting up a gears in a diff in a car...which have a spec as to the amount of 'float'
So has nothing to do with the prop as far as I can see or understand.
If u can pull on it and have movement the Prop nut has not been torqued up , it is the wrong prop for the engine , or wrong thrust washer or top washer for that prop.....It maybe a Prop from a different brand (merc or suzi whatever) which I believe one can use by also using different thickness rear thrust washer and/ or spacer washers