Hi Axel,
Very nice to see that it is working well for you - thank you for sharing the video!
For the contacts, you should have a look at the contact report tutorials in the physics demo scenes:
Unfortunately, I found that we have a bug with SDF rigid body contact reports causing a crash. But I am looking into it and we will try to fix asap (but it might not be fixed until 2022.2) - I will update you.
Philipp