No problem, we've got a lot of users in the forums who can help you with your questions, just drop your questions in anytime.
Hmmm... I have a L1020 but here's what I've got for your questions:
1. In the L1020, the tint (sometimes greenish or bluish) only happens under certain lighting conditions and when taking a photo of certain subjects. For example, when I try taking a photo of a red gate up close, Lumia Camera tries to compensate for the over-all redness of the photo and turns it slightly purplish. Just like you, I change the manual white balance settings to fix it - usually the daylight setting is the best. Under daylight, I usually get no issues with white balance. Do you?
It seems to be mainly a software "issue", since a few updates in the past have "improved" the color rendition of Windows Phones. However, it also has something to do with how digital cameras in general - that they always need to determine a sort of baseline for the overall color profile of the scene (rather than a fixed color sensitivity as in film cameras).
2. There seems to be no way to save that. The only setting that is saved in Lumia Camera is the flash setting - the rest needs to be set manually each time the app is exited.