Nice that you like it 
Well, if the cells are unprotected (or not very long) you’ll have no issue
Are those the white ones?
Yes, the i3 as weel as th Z821 create some rings due to the lens, gasket and bezel. Blackening them or making them “matte” helps avoiding some of that reflection.
Ahah, don’t enter the zoomie twilight zone, or you won’t get back from there 
This is a nice small light, with a better UI it can make a good EDC, but to each its own 
Glad you like it! 