hey maheep 
i'm playing nl10 too and have been reading about AF and Afq recently...
basically i've removed AF from my HUD now because i believe it to be thoroughly misleading! as you probably know, AF = (bets% + raises%) / calls%. and so this doesn't take into account the percentage of checks and folds made by the player in question. Afq = (bets + raises) / (bets + raises + checks + calls + folds). the problem is that AF is calculated alongside VPIP and so someone with a VPIP of 70 might have a "passive" AF, but actually it isn't passive at all. similarly someone with a VPIP of 18 might have an extremely high AF leading you to believe they have many bluffs, when really they are just betting whenever they have it - which is often because they are so tight.
i have heard numerous experienced players explaining how bad AF is and i've very often leveled myself into calling someone down because of a high AF - it never worked out. it also makes me question whether or not we are also levelling ourselves into folding whenever we are faced with action by a "passive" player who may well not be all that passive at all.
i try not to put too much emphasis into stats now and so i'm not too knowledgeable with them. maybe someone more experienced can jump in and explain the pros and cons of these stats and even how best to use them 
about the AFs you listed, id say...
maniac.........>4
aggressive....2.8 - 4
passive........1 - 2.8
big station....<1
and i can't really talk much about Afq because i've only just started using it. i would say ~35 is standard aggressive but meh.
i was going to create a thread about this myself and would really like to see some discussion 
Lewis