Well, compressing the spring the way you did is highly dangerous. (Believe me, I know). When compressing it in a vice like that so you can wrap wire around it, the spring can pop out and smack you in the face (again, hehehe, I know from experience). Easier to buy a 15 dollar tool, then to end up with a cut/bruise/lump on your forehead. I'd rather have the right tool (especially considering how cheap they are) then to sacrafice safety...That's just me though
As to the grinding the point down, that's ok, but with the socket extention, you don't really have to recenter it as it grips the hole head of the pin.
If you develop egging, the best way to take care of it, is to weld the hole up, grind it flat, then redrill.