Kitchen drain and pipe installation too high?

Hello everyone!

I hope there are a few experts here who can tell me at a glance whether this is alright or if something urgently needs to be changed.
The plumber completed the rough installation last week. This raised two questions for me.

1. The builder and I placed special importance on the fact that the lowest level (slab) is sealed with bitumen. The plumber has now fastened all the pipes with hammer anchors, thus piercing the sealing. The answer was that this is always done this way and is according to the standard.
Is that correct? Does the anchor basically close the sealing layer again (similar to the vapor barrier) and am I just worrying too much, or should this be handled differently?

2. The builder apparently set the kitchen drain connection too high, which is why the plumber had to connect the dishwasher and the sink together. The sink connection with the "snail" going in a circle once confuses me. I am currently concerned about clogging in the kitchen because of this.
I asked why they didn’t use a T-piece to connect, but according to the plumber, it’s not possible otherwise and the snail is okay since only 45° bends or less were used.
If all that is really fine, that’s good. But I want to avoid irreparable damage later.

I would be very grateful if someone could quickly give me reassurance or let me know if I need to go into further detail.
Thank you in advance and best regards

1. Depends on your base slab. In our case, the slab was also sealed with bitumen, but according to the site manager, it wouldn't have been necessary. They do it anyway. Our plumber also worked with perforated tape. After installation, they brush over it with a bitumen coating.

2. To me, it all looks appropriate. The main thing is that the slope was considered

Regarding 1. I cannot judge.
Regarding 2. The drain is well installed. The wastewater is discharged in the direction of the flow. This way you have the best flow characteristics.

Thank you very much in advance for the quick responses. I would be happy if someone who understands the background could say something about point 1. I really don't know how critical the topic of sealing is. Regarding the construction: The floor slab rests on strip foundations and, of course, rolling and XPS insulation. Above that, 25cm of concrete

1 is not a problem. Bitumen remains watertight when nailed.

1 is not a problem. Bitumen remains watertight when nailed.

That sounds good already.. so that means I don't need to apply a bitumen coating over it?