Adjusting new clutch

No, the cotter pins just hold the studs so that they won't slip toward the underside of the pulley. The dogs and toggles could disengage if they did. The double-sided clutch facing just slips onto the pins and floats.

I think your clanking noise is from the floater disk (the cast one with the gear teeth on the inside) slopping against the teeth of the driving disk. Most I've heard make kind of a tinkle sound. It's really more annoying than problematic, but to get rid of that noise, you'd have to replace the worn part or parts. As long as the clutch works properly, engages/disengages smoothly, and does not slip, the floater disk will "get together" with the driving disk as the clutch engages, and will work fine. The trouble can come when the floater is so sloppy that it can wear a small ridge on the driving disk teeth and cause the clutch to hang up a bit.

Frank-in-Tallahassee
70D // 855

Some folks use a common torque value to bring all the nuts up to the same force and position. If you have a torque wrench handy, and all the studs have clean threads that might work fine.

But I've just always turned the nuts on as evenly as I could, so that I judge that they're all holding the same amount. You can even look at the studs and sort of judge if you have one on a turn or two more than another. Then I turn them in pretty much as far as they will go , and then start backing them out evenly. Then I generally go too far out, and make my last move inward which is the best way (so the last move is toward the work). That's just a habit of mine to keep the play to a minimum.

Sounds like you're on the home stretch !

Frank-in-Tallahassee
70D // 855