Normally you would stay in the Non-Schengen area and enjoy Lounge 52. If you want to go out for a smoke on the bus platform or so, you must pass passport control and that is hit or miss in terms of queues. Then you must go back via security and passport control again. You will have priority security lines since you fly J. Last months when I did passport control entering non-Schengen airside that was fine.

I do not know about lockers since never used them in AMS. NOrmally if you check your backpack as luggage in LAS that will be labelled through to Dublin.