-snip-
I got a query , i see "Nuke user: N/A in topic #0 by member #509593"
What does Nuke means here? Banned ?

"Nuke" is something staff (esp. lower ranks) can do to newbies. It silently removes all their posts and bans the account. Its typically used to fight spambots.
That sounds really awesome , i have seen many newbie's making useless posts , so they must be spambots. How does a mod get's to know about it? Will it be good if i report them ?
Just one more question, You said
staff (esp. lower ranks) , as i know there are two types of staff
#1 Administrator and
#2 Global moderator , so except Badbear and Theymos , everyone else is lower ranks staff or are there any more staff ranks ?
Mod knows by looking their posts. Their posts most probably will be rephrased. If you think a newbie is spambot, report it and it will be nuked.