Nope...you are just watching a very experienced crew, who clearly fly together regularly and know what they are doing, enjoying their profession in a region that hasn't outlawed fun in some PC backlash against life.
I used to fly the same technology in a similar scenario...we used to smoke but admittedly not through a landing...perhaps there was a little more chit chat than would be considered proper but then they were flying a visual approach and I don't speak their language so am unsure how much was non operational.
The captain flying from the RHS was clearly concentrating on the flying and not partaking of most of the chit chat...the remaining crew members responded to commands for config changes and ran the checkists in a timely and professional manner. It was a joy to watch actually..lovely flying and a beautiful landing...727s don't land themselves unlike some more modern aircraft...727s and their ilk are mans aeroplanes.
I firmly believe having watched them that had the weather been bad they would have responded in an equally professional manner and the film would have had a completely different 'tone'.
I envy them their job...but not their pay probably. If I could earn what I do now flying a 767 doing what they are doing in their 727 I would be there in a fast minute.
As far as the ground prox...that was a glideslope warning and he was flying the Papi...from time to time I set that off too on a visual approach at my home port...but my airline, like his doesn't have ACARS flashing off a message to BS castle 1/4 of a second later. It could be as simple as a slightly steeper than nominal GS in order to clear a chimney or other obstacle that is not a consideration on a visual approach...which is exactly the case where I live.