Engine running on after ignition cut

[muhoo]

I've noticed lately a couple things on my 98 E350 7.3L OBS:

1) The engine seems to run really HOT. The coolant temp is normal, but that's what it's supposed to do. But the doghouse gets hot, the cab gets hot, and the engine doesn't seem to be working hard enough for all that heat.

2) The engine runs for a couple revolutions after I cut the ignition. I've had this van for a couple years and don't remember it doing that before. I'm also getting a high chirping sound out of it when it idles after it gets hot, and after I cut the ignition too.

3) The fuel pump may be weeping, but I can't tell because I've got another fuel leak from someplace in the front of the engine, which I haven't been able to find in 2 years of working on it. It's maybe from the return fitting into the regulator, I don't know. I've replaced a bunch of parts, the return hoses, and all the o-rings on the bowl, then gave up after none of that helped. It only leaks about a half a teaspoon a mile so it was putting off dealing with it until the weather gets better.

What could be wrong? Is it running too lean? Do I have to deal with this now or can it wait a couple thousand more miles?