1. Yes. If you tell the IRS you are a foreign resident you are entitled to a tax deduction of $87500. For example, if you make US$100,000, after your foreign earned income deduction of $87500 you will owe tax on $12500.
There are a handful of other things that will help you in addition to the foreign earned income deduction. You can deduct housing expenses (based on the city in which you live), you can deduct foreign taxes paid, etc.
2. Yes. CA sucks and is the only state in the US that will tax foreign income. But...there are loopholes as you have mentioned. Check out some other options. You can - under certain circumstances - sign forms stating that you won't return as a CA resident and then get out of paying state tax.
3. See answer to #1
IRS pub 514 is actually helpful unlike everything else the IRS writes. It will walk you through all the turns. Check it out here:
http://www.irs.gov/pub/irs-pdf/p514.pdf
PS: (slightly off topic here) don't contribute to a Roth IRA this year or any year if you figure out that you don't owe tax as a US citizen living abroad. You will get a big fine if they ever audit you. The logic is that since you technically have no after tax income, you are barred from investing in tax protected retirement accounts.