Did he get his horns surgically removed? Or loose them in fight? They never explained why the stranger didn't have steef horns.

No, they didn't. And we don't know why.

Some people (myself included) think he had them surgically removed at an earlier date. Others just think he's still too young to have them, or that he may even be a female steef.

He makes quite a few jokes about his.. um.. man-ness. I doubt he's a girl. Did he have stubs of horns? I haven't seen the cut scene in awhile.

yeah, I knew Stranger was a steef long before the game came out. I remember when we thought that was his name :D I havn't played the game yet but I knew too much before it came out

heh...moolah for killing a steef huh?
*walks into Sekto's Office*
Me:"You wanted a Steef?"
Sekto:"yup, where is it?"
Me:"right here" *shoots sekto* "Now wheres my moolah?"

on doc's sheets you can see the rest of cut horns on stranger's head (ala Hellboy)
So I guess Doc removed them during one of their previous meetings