Engine stalls

Questions:
1.) After driving 100 miles car loses power then stalls, now it stalls less than 50 miles. What is the cause?
2.) Engine used to make ticking sound now makes a loud humming sound and engine vibrates. What is the cause?
3.) Smoke was coming from engine. What is the cause?
4.) Coolant is full past hot mark when engine is cold. Is that normal and how would it affect the performance.
5.) Fan at front doesn"t turn when idling. Is that normal?

All this is after the mechanic said he replaced engine and now I don't want to take it back there.