ok well first if you need help with the set up with the basic controls go 
herefor customizable controls go 
herefor hitting the player try going 
here and then go under actionscript then collision detection
ok and as for health you could go 
here(that flash would also help with the other 2)
ok and one last thing 
here is a list of other helpful tutorials that were made in flash
hope this helps at all 

if it doesn't just say so