yes if a lvl 2 attacks a lvl 6 lvl 6 can hit back. Not sure how long as in days you can attack said player. You will also not be made an outlaw as long as you only attack those that attacked you first.
I think there is no time limit, only the number. So you forget attacker #1 after you've been attacked by attacker #16, who takes his place in your list.
Don't know if it's fair though. I'd introduce a limit of 3 kill-you-backs (for fair chance to get a drop back if one happened, and for general retribution )
yeah, it's long... I have just seen so many players frustrated and even uninstall completely over the lower-level-mechanic abusing cowards that I have no sympathy left for them lol