Please help, no one else I have talked to can

1998 Ford Windstar 3.8.A few problems.
1) drive belt keeps slipping off
2) smoking coming from under hood on side of engine where belt is, temp gauge not showing hot and smelling a bit like coolant
3) speedometer/odometer stopped working but all other gauges including RPM works
4)van wants to die when coming to a stop or slowing to turn. Not every time but a lot
5) right turn signal don't work and makes a funny noise if flipped up all the way but works and no noise if hold it just below the point where it stays on by itself