That strikes me as sick and inappropriate for any age, sorry.
Out of context. GTA walks a very fine line, always did, and it is ONLY okay from a very particular point of view. It’s meant to be funny by being completely outrageous and not realistic. The whole thing is daft. If it weren’t, it’d be sick.
No chance.
Definitely not suitable for a 9 year old, of course, because you don’t have this context. Probably not even suitable for many 18 year olds, I’d stick a 25 certificate on it if there were such a thing.
It’s not about blood guts or swearing, it’s because it presents things that are awful in a black comic way.