If you pay too much estimated tax, that doesn't cause any other problems, AMT or anything else. It's just withholding, and if you overpay, you get the difference back as a refund.
You are required by law to make estimated payments. However, the IRS will not enforce a penalty as long as you pay enough into the system to satisfy one of the rules quoted above. If you correctly calculate and pay the bare minimum, you won't be penalized but you will owe the rest when you file. Again, paying too little doesn't change AMT or anything else, it just means you owe a big bill when you file.
