Thanks Rocky. I'll pull this barb out and figure out a replacement later...
As far as the thermostat is concerned, I did some digging and found a few applicable threads:
https://pantera.infopop.cc/top...this-argument-please
https://pantera.infopop.cc/topic/351c-thermostats-1
https://pantera.infopop.cc/top...ter-pump-by-pass-cct
https://pantera.infopop.cc/top...ifacation#6880012344
I'll have to check my water pump tonight to see if has the bypass hole or not.