You're gonna have to teach me how to quote in talk pages haha
Regarding the salutes (and the goose stepping), I'm not a DDR historian but there are archive pictures online. Here is the NPA in a parade: https://c8.alamy.com/comp/PA03N7/parade-of-the-peoples-police-departments-volkspolizei-marx-engels-platz-east-berlin-germany-PA03N7.jpg, showing they did not perform the goose step on the regular (which is associated with nazi germany these days).
However, they did perform the goose step, there's two pictures on Getty: one described as a "tourist attraction", and the other during the changing of the guard at the anti-fascist memorial (also for tourists or public display?). Seems to me that goose stepping wasn't a common occurrence and reserved for specific ceremonies.
And here they are saluting: https://media.gettyimages.com/id/541073579/photo/german-democratic-republic-otto-grotewohl-11-03-1894-politician-spd-sed-gdr-first-prime.jpg?s=1024x1024&w=gi&k=20&c=Y2kirlNxWCwnFPMUDmOT_zUPIWXAPhODk6uVXhN_VIs=. Otherwise they also seemed to use the typical salute we associate with soldiers today, same one as above but with the palm facing down.
I haven't been able to find the salute the kid did and never saw it in my life before, which makes me wonder where he got it from.
Here's Hitler with an (almost) right angle salute: https://imagenes.diariodenavarra.es/files/image_477_265/uploads/2021/03/19/60ae33ce4702a.jpeg, which shows precedent.
It's unfortunately difficult to get this information regarding the NPA specifically in the DDR as most searches have an anti-communist bias equating the NPA to the Wehrmacht and of course most results are about the nazis as soon as you enter the word "german".