What stats would I need to bring in a decent profit per hour at Chaos Druids?

I'd recommend at least 40 attack, 40 strength and 40 defence. That should maximise exp per hour. of course anything higher will only help your cause! 

im botting with 40 attk , 60 str, 20 def, atm

Yeah like Katy said you don't need overly high stats. Obviously the higher the better but to actual be effective 40+ should be fine.

Is defense necessary if you can smack them real nice and hard on the first hit? and when does defence start to fall off? I.E. is it better to be 40 attack 60 str 20def then 40 40 40?

 

20 def and you're golden, defence wise.
I would suggest 50 strength at least. 40 attack. (If you want to kill them in a relatively fast manner, obviously lower strength works)

Oh, also. My 1def is doing just fine, but he is pretty high in combat stats and hp.