Well I just spent the past 2 and half hours training in the lag -- 28% exp, 3 lach symbols and 21 nodestone when the USC banner appeared. Shortly after, a smega popped up about rollback rumors.
I don't mind maintenance, scheduled or not, because it means they're fixing something but if a rollback does happen and the stuff I worked for disappear, i WILL complain.
The fact that you have lag doesn't mean there is a upcoming maintenence, maybe it's your connection or just your PC. I was ingame the whole morning and I had 0.0% lag. So yeah, next time it happens you should complain, not to Nexon but to whatever causes the problem (PC/internet).
The easiest way is to just use a different damage skin, but if you want the classic orange/red numbers, the only way is to use the thing that resets your damage skin to the original, I don't know what it's called.