> In any case, it's just impossible for me to figure what is the issue. I could spend a inordinate amount of time guess-shuffling code around for no result.

I’d caution against the shuffling code around to try to reverse engineer the approval rules. I tried the same with a similar extension (Adblock Fast) that got rejected for similar reasons (no reasons as far as I could tell). Result: my dev account got automatically suspended. I had to get a Google friend to get me unsuspended. Google seems to have added very aggressive automated approval and suspension rules. I’d reply to their email and see if they reply back first.