*If you don’t do everything on your own :-( * *eye roll*
You can also break out half bricks and in the end the edge will be plastered anyway, then everything is fine.
Basically yes. But I really wonder what kind of special school dropouts work at some construction companies. Using Poroton in the door frame where aerated concrete should be, well okay. But not also calcium silicate bricks. It can be done if necessary, yes. But why talk beforehand about how it should be done?
Of course, they should at least – and I do not see that on the photo at least – first make a break (joint) there and secondly of course also a lintel. I would drive nails into the upper corners (both on the house and garage side), which can later be easily located in the plaster. And/or measured.
The calcium silicate brick will definitely not be laid flush with the door lintel.
No, a 2 cm separation/expansion joint is intended there.