Agree, it makes sense to go to MLS teams just to make money or live somewhere else. I think it is no different than Arabian teams. You can go to these teams to earn money in the last years of your career, but it wouldn't make much sense to be here at a young age. Prevents you from progressing in your career 
I agree with you on this. I also think that young football players should continue to play football in the top leagues to showcase their talents. However, it is definitely a better option for them to go to Arab teams or MLS when they get older to make more money and play safe football in a less competitive league.
It is an undeniable fact that Milan really need a striker right now. They can't move on with Giroud and Origi anymore as none of them would be reliable for bigger successes. Giroud has been better than Origi at least but still he is getting too old and he might not be consistent anymore. Origi is also even far away from his performance at Liverpool. Lukaku was on Milan's agenda but they must have given up their attempts for him after hearing that his priority is joining back Inter.
Ibrahimovic also left football at the end of last season. He didn't play as well as Origi or Giroud recently, but he was in the squad and was an effective football player. Italian teams really have good success with older players. However, they may encounter such problems from time to time.