Slave cylinder mounting and adjustment questions

[lippy]

I just received my engine from Brent yesterday and am getting ready to drop it in this weekend. I'm a bit unclear about the slave cylinder mounting and adjustment, so I'm hoping for some color and clarification. As you can see in the photos below, interference between the slave and the edge of the bell seems to prevent the slave from being concentric with the hole in the fork. No big deal, I can grind down the bell a bit. But I want to make sure I get the mounting and adjustment right.

My questions are:

1 - After I grind down the edge of the bell, should I just eyeball the rod and fork to get them very close to concentric, and then drill and tap a couple of holes in the slave mounting bracket and block flange?

2 - From the photos, does it look like I need the ERA spacer (they didn't think I would)? What is it's purpose?

3 - I will cut down the threaded rod. Doug also recommended I use it to push back the plunger in the cylinder all the way, and then back it off 1/4" so there is play between the cylinder and the fork. Not sure I completely understand, so any additional color on how to adjust (and mount) this would be appreciated

4 - Do most people use a spring? If so, what type and tension?