Sollozzo would have never expected Mike to attempt a move.
1) Mike wasn't at the meeting with Vito and Sol.
2) Mike had no track record of being in the Family business.
I don't care what Mike told Tom and Sonny,it was absolutely personal.
Had Mike not arrived at the hospital when he did,Vito would have been dead. In Mike's mind, McCluskey was a scumbag outsider who sold out to Sol.
For what it's worth,at least with Sollozzo, it was part of this "Sicilian thing".
And as we all know,Mike had to kill McCluskey because "he injured me",first by setting up Vito,then by breaking Mike's jaw in public.
Christ,Mike killed his own brother for no reason other than Fredo being a doofus who got played by "that Jew in Miami"
As far as the whole restaurant set-up,well "the Corleones played this one beautiful"