It's probably the spacer you added. You've changed the dish of your wheel by that same amount. I usually grind that hanger mount screw down flush. You don't want that much of a gap. The chain can actually rub a tiny bit as not too many people can crank a 12t gear on a muscle bike for very long. That 8 speed cassette is super wide already. You want it as close to the drop out as you can get it.
Spoke protector looks good. Make sure you trim them zip ties...
Edit: Here's a pic of a 9 speed setup. You can see the flush hanger bolt. This is all the gap you need. Just enough to let the chain shift on to that last cog.
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