Originally Posted by
corporate-wage-slave
They do for all lanes, but I suspect the waving of a Priority Pass card would do the trick. It's ok to go shopping in T3. I don't actually know for sure, however, and you can certainly say that you don't have a boarding pass yet and need to collect it from the customer service desks, which are the other side of security.
There is no problem entering T3 via the "purple route" without a boarding pass.
Using the paid lounges in T3 is advertised in Flight Connections in other terminals. So it is indeed allowed.