As you could tell by looking at our handbook, we kind of look at ICAO doc 4444 as a very nice guide <G>. We don't use it much nor do we use a lot of other ICAO procedures. We look at what works here and use those. There are those who want to make our book look much more like ICAO's but there is indeed resistance to that for many reason...
As to handing over separation responsiblity, we do that when the aircraft reports the other aircraft in sight and we tell him to follow him. It is the ALL the pilots responsibility to follow and avoid...
regards