May be better make 1st lvl characters 100% resistant from players' attacks and steal skill and ofcouse same to them, they can't attack and steal from others, include others 1st lvl characters. Because also you can see some 1st lvl 10 STR 10 END 10 AGI others min, with Unarmed 90% or 10 AGI and steal 50% (not so high but.. it's only 1st lvl).
But i think the best way is to leave everything like now.
May be make something like "childkiller" karma, so it'll be added "noobkiller" karma, so PKers of 1st lvl noobs will get very very very bad reputations with all, etc. But... how to see 1st lvl char or no? 15 lvl can wear blue suit and remove brahmin's shit too. ^_^