2003 E150FPXSTD FICHT Shifting problems

I have an Evinrude remote control - Concealed Side Mount style on a FourWinns 180 F/S.
I seem to have two possibly related problems. One is the engine doesn't return all the way to idle speed when I bring the throttle back, it sometimes takes about 15 seconds and hovers around 1200 RPM. The second and more concerning is the motor won't always shift into neutral and the throttle handle feels like it is binding. It will sometimes jump over neutral and go into forward or reverse depending on which direction I am coming from. This happens even if the motor has returned to proper idle speed around 650 RPM.

The odd thing is that I have tried it in my driveway with the cover off trying to see the problem and I works just fine with plenty of play around neutral. I have tried to lube the cable at the motor end to see if that would help but it had no effect. Any ideas on where to look or what to try that may be relatively easy?

FYI: The motor had 227 hours on it when I purchased it this spring and now has approx 10 more hours on it.