Based on what I read, I don't think the glowing manifold is necessarily a concern. I just put some NGK TR55 in mine which are cooler plugs, and will see how they look in a week. I do mostly heavy stop and go driving, with a one mile long hill everyday on my way to work, so maybe my gas mileage will always suck. That'* the price of driving luxury and living on a hill.
I also ran a scan on my car with an experimental homemade interface and free software, and it came out clean on all malfunction flags. It did indicate some knock retard when I did some heavy acceleration and going up the hill. This is before the new plugs. Premium gas around here is 91 octane. I'll have to try the scan again in a week or so after the ECM has a chance to learn the new conditions, to see if it affects it.
Since I replaced my O2 sensor and cleaned the TB, it does idle smoother, and lower than before, around 750 RPM.
Oh yea, I also took out the MAF and cleaned it very carefully with a Q-tip and denatured alcohol. That seemed to smooth the idle a little as well. I got that idea from reading a Ford truck thread. It didn't seem to hurt anything.