Your plug looks normal coolant will clean them up right away in my experience.As far as water coming from exhausted coolant has a very sweet smell,and would probably become worse as engine warmed.And yes there is a 5/8 -3/4" tube with an o ring that may be suspect in that area.Heater hoses on back of engine.And coolant lines running through throttle body possibley a bad gasket there would allow some coolant into combustion chamber.tech section stickied on this forum should have some good line drawings of these external coolant lines.

90 LWB,Treehugger
97 Subaru Legacy L wagon