Rough Engine with squeak and slight coolant leak

I've got a 1997 OHV 4.0 V-6 2WD with 125k miles with the problem mentioned in the subject line. The coolant leak started first and I've haven't been able to isolate where it comes from. I just get a few drops on the garage floor overnight with a puddle the size of a dime. The squeak has been intermittent with a belt or perhaps an accessory being the cause. The rough engine problem started yesterday. It occurs at idle and the truck feels "strange" at highway speed. It has a vibration like a rough tire but you feel it through the body of the truck and it varies with speed and accelerator pressure. Does anyone know of a problem that might cause all three of these issues? Any comments appreciated. TIA