Yes, it is possible to drill concrete with it. This drill comes with 5 concrete bits ( 4 mm / 5 mm / 6 mm / 8 mm / 10 mm ).

Normally everything is compatible (same brand) as long as the voltage is respected :)

Yes, that's right. :)

So if I have understood correctly, then yes: you don't need an extra key to fix something, but turn it conveniently closed I am thrilled with the machine, it fits very well in the hand and has a lot of power....