"I had to quit the Cutler protocol (100mg ALA every 3 hours, day/night) because the ALA is causing the skin on my back to break out in large boils, and small sharp "pimples" on my face, not to mention my skin gets very itchy/red every few hours. I'm currently taking just 100mg in the morning + a detox bath once a day. "

100 mg of ALA every 3 hours is a large dosage. One needs to build up to that. I started with 50 mg of ALA every 3 hours, then found that I needed to back down to 25 mg every 3 hours. I suggest that you wait a few days, then try doing a round of chelation using 25 mg of ALA every 3 hours. After successfully completing 2 rounds of this this 3 days on 3 off, then you could try using 50 mg every 3 hours, and stay at that dosage for a month or more. If you want to, you could add 25 mg of DMSA every 3 hours to your regimen.

Taking one dose a day of 100 mg ALA could make you much worse. Stick to dosing every 3 hours, with 3 days on and 3 days off.
your skin problems might not be from mercury, but from candida. Candida might overgrow greatly during chelation, especially if you eat plenty of sugar or alcohol.

How long ago were your amalgams replaced? How many did you have?