I have a July flight LAS-AMS-DUB on KL (WBC) with a 5 hr layover there and 3.5 hr back. Flight history shows arrival is usually gate D4, departures to DUB usually from D6. I haven't been to AMS in four years so I can't remember what's the order/locations regarding passport control & customs.

On a Schiphol diagram, once off the plane it looks like I don't leave the Schengen area to walk from D to E/F and go up two floors to lounge 52. The KL lounges used to have nice smoking rooms. No longer.

I'll have a carry-on backpack and a small laptop purse. I'm hoping to put everything except for my passport, boarding pass and cigarettes in a locker and head outside for a couple of cigarettes. Do I need my own locks for the lockers? Anyone know the rough size of the lockers? Limited to one per person? More importantly, can I get back into the lounge to retrieve my luggage?

To get outside, the diagram shows there's an elevator near the lounge. Take it down to baggage claim. It looks like there's passport control (or is that customs?) at the base of the elevator. Go thru and out the door to the Plaza.

Coming back in from the Plaza, what's the situation with security? I assume I get ST Priority (via KL WBC and DL Platinum). Are there security lines in the baggage claim level or just on the departures level? On the diagram, both passport check/customs and security have the same symbol - so it's hard to tell which is which.

If I checked the backpack in LAS, would it be checked through to DUB or would I need to claim it in AMS for customs and then re-check it in for DUB?
TIA.