Hi,
About the yellow, check pano Yemekhane from the tour. Overall color in the image is yellow. This comes when using auto white balance while shooting places with inside and outside light mixing. Two ways to solve it.
1. Set white balance manually while shooting. (Recommended)
2. Fix the pictures after shooting in Photoshop. If shooting in RAW, just use the white balance droplet to pick white from some paper on the pictures or play around with the white balance slider till you think it's great. I usually check if my WB is correct by raising the saturation of yellow and see how much it affects the picture. If much, WB not right. If barely do nothing, then should be fine. Most of the time by trusting your eyes will get the wanted quality.
Shooting in RAW is the way to go in every single situation. The data you lose when shooting only in JPEG is huge! You lose the flexibility and you can't fix things easily in the picture, like White balance and noise.
For easy way to make panoramas, check Kolors panorama programs:
www.kolor.com
Easy, not so expensive, powerful and co-operate with KrPano :)
For easy way to fix zenith and nadir, use this plugin for Photoshop 32bit:
http://www.superrune.com/technical/software_supercubic.php
That's all i can do to help you now :) Hope it helps you! Keep up the work!
Regards,