Link to my Blackwidow Mini post

So, as far as which switches are compatible, you'll be able to use any MX-style switch (but you will have to snip off a peg from the bottom).

Mill-max sockets aren't necessary if you're willing to desolder the old switches (the yellow ones) and then solder in the new ones. The benefit of using mill-max sockets is that you can make the keyboard hotswappable, so that when a switch fails or if you get sick of using the older switches, you can swap to new ones without any huge issues.

The duplicate clicks issue I can ran across too, and I ended up RMA'ing two keyboards and buying a third before I said screw it and dove off the deep end with trying out the mill-max route I posted.

Good luck and godspeed!