your seedlings is to young to be root pruned, they need all the feeder roots they can get for there survival, i have a seed flats were i planted them and until now they still in there happy and striding, they are 76 days young, and im not planning to move them till they hit 90,
seedlings needs lots of water, but not like drowning, let them dry out grab a toothpick poke your soil if its moist or its dry, then bottom water them, you can start feeding your seedlings in small doses also
and the name desert rose means they cannot be watered to much, all plants love to be watered, they called desert rose because most of these species came from arid deserts,dry lands etc, and all these species that grew in the wild are all adapted to its harsh environment, but for us, we can control that, we can water them, we can feed them, we can nurture them, as long you do it right your plants will love you,
im not sure about the weather in Norway, try to buy a grow light for there artificial light for now so that they can get proper heat everyday, and put some heat mat if its really cold on you area,
pinching, you can pinch them if you want to force branching, every species differ, some will show branching by the time they are born, and some don't have it will later on, for me i don't like pinching that much for this species, i want to grow mines in its natural form, well this method will be for those i hand pick to raise, and the rest will be experiments those i can prune, slice them up, and so on...