I have enough miles for an ecomomy miles reward flight to LAS (although looks like have to travel to LAX initially as no rewards on LAS as usual) and an Amex PE upgrade. I intend to travel with a mate, can i give my miles and upgrade to him and then travel myself in a paid PE seat so i can obtain the miles and tier points for the flight in the paid seat and we share the total cost
Yes, you will need to book the ticket, but you can use your miles for to buy a ticket for another person. Remember that with the AmEx PE upgrade voucher, there needs to be PE (U class) seats available only, there doesn't need to be any economy seats.
Neil