how about up/down sconce lights around the room?

If the main function of the room is home theatre, I’m not sure I would invest a lot of money and ceiling height into overhead lights. Sconces are an option, or you could have cove lighting installed near the ceiling around the perimeter that gives you soft lighting that doesn’t interfere with your theatre experience. It would be similar to your inspiration photo but without the down lights. Then fill in with lamps as needed if kids are playing and need more light. It’s rather simple - you can have an outlet installed on the wall that’s controlled by a switch. The outlet is hidden by crown moulding and you can run rope lighting or strip lighting in the crown.

We would like to use the room a lot for playing with the children / hanging out - so think we need more than just cove lighting.

Do you think a ceiling with recessed spotlights at a height of 2m 12 cm will be too low?

By my calculations, that does not meet the International Residential Code for ceiling height - which is 7 feet or 2m 13cm. Although it's very close and if you just have a dropped area around the perimeter, and not in the center, your building inspector may be fine with that. I personally think it will feel too low for the whole ceiling to be dropped and if it were my house I would layer in light from sources other than the ceiling. Down lights are the least flattering type of lights anyway. You will get better ambiance from layers -- lamps, sconces, cove lighting.