Hi Simon Stingray,

As I understand it you can buy anything at Duty Free at LHR to carry on board.

If you are travelling with checked luggage, you will need to collect it at LAX before rechecking with DL for the flight to LAS. If this is the case then you could buy the wind duty free at LHR then once at LAX and clearing customs, put the wine into your checked luggage for LAX-LAX ( this will not work if you are only travelling with handluggage)

3 hours should be plent of time to connect. I have always found that T2 customs and Imigration is quick.

Walking form T2 to T 5 is possible by turning right after exiting T2 , then passing T3, follow the path round the bend, past Tom Bradley Intl Terminal, round another bend , past T4 ( American Airlines) and then T5 ( probably a 10min walk maximum)

Regards

TBS

PS I do not think the shopping at T5 will be that great based on the shopping experiences at the other Terminals.