1990 Subaru legacy as awd wagon it is overheating

I have a good one for you. I bought a Subaru legacy
wagon for $380.00  he told us it had an over
heating problem. That 2 years ago he had
everything replace on it. Come to find out the water
pump had been replaced  4 years ago. So we
replaced that. Tested it. Still over heating while
driving.  Then we replaced the radiator thermostat,  
hoses, timing chain belt, (it needed it anyway)
radiator cap, put blue devil head gasket stuff in it.
Also did the pcv and spark plugs and wires... My
husband is a mechanic.... Flushed it. Oil change.
Found out it doesn't like antifreeze on really hot
days and runs on water like no tomorrow.  But if we
don't keep an eye on it it has no water in it and
when it did over heat with radiator fluid in it it
would spray out where the hose goes in on the
over flow. We replaced the radiator there was a
small hole in it , I found that. We haven't changed
the blower yet. It only works when it wants to.
Driving down the road and it turns on by it's self.
And the fans work great to. Any ideas?