GF, the reason that "request" is used without adding what is wanted is the same way that ATC calls and says "Springbok xxx, Joburg" without specifying what they want. It is a way of making contact in an environment where both the flight crews and ATC may be preoccupied with something else and the request is usually non-standard. It does no harm!!
As for fully ready, this comes from more advanced ATC environments where clearances are obtained at or just before scheduled departure time and ATC will come back with "Speedbird XXX, confirm fully ready?" Fully ready means that when they have finished reading back the clearance they can hand you over to ground for push and start.