Hi,
dont have much time, so just briefly:
- checker pattern in material editor BEHIND balls is a feature, you can disable it with that show-checker-background button in max UI
- checker pattern in scene with BUMP occured in some older builds and is fixed now. Update your build to fix it!
- you will get the best results possible with as low filtering as possible, provided you don't care about time. You can globally disable filtering in devel/debug tab of corona settings (the tab has to be turned on in the about tab), BUT
- you absolutely MUST have filtering enabled for bump to work correctly! Due to the fundamental nature of the bump algorithm it requires reasonable filtering (value around 1, NOT 0.01). You can use displacement* and/or normal mapping without filtering, but NOT bump mapping!
- all of the above assumes you use the latest version that has the filtering fixed. If you still experience some problems with filtering there, report it as a bug.
* actually, filtering is ignored for displacement mapping