My knowledge is more from an economics and jobs standpoint. I'll admit I know less about the schools. Both entities provide a significant amount of jobs to citizens of Anaheim (and other cities) which in itself is a tremendous benefit to having the team. Let's say they left and went to LA, that would leave a lot of people without jobs unless they commuted. This would in turn leave less people spending money on other services within Anaheim which would continue to snowball into other problems. The trickle down effect they both have is massive. Now if they went to another city close by, the impact would be significantly less and many of the same benefits would still exist for Anaheim.
At the same time if Moreno tried to get the city to finance the new stadium, you could argue that the citizens of Anaheim are better off if the team leaves. This has been a bit of hot topic lately and a lot of research coming out shows that the city is almost always better off not helping pay for new sports infrastructure. Mainly because of the trend for teams to move around more than ever before, which leaves a city like Oakland paying for the coliseum another 20+ years after they leave next year.