Re: SEDM approach
SEDM is very complete however you don't need to do all those steps to use a form W8BEN modified or not.
Nearly any bank around here will grant an account based upon a form W8BEN. Some even offered it. However ALL banks around here accept it only upon presentation of a foreign passport or Mexican Matriclardo ID card. You can find this online in how to open up accounts...for example...buried on PNC Bank's website even.
My experience with any bank and handing them anything on law, citizenship, etc.:
The banks LOOK at the legal paperwork but come back with: "Our legal department has no comment on your paperwork. We write our own policy on whom we accept for an account. Our policy states we need a foreign passport or Mexican ID card with a filled-out form W8BEN. Sorry!"
Just in case you're thinking of using the law sections on them, the banks are WELL prepared for that one. The bank association puts out a newsletter. In there was a discussion on that topic as many people approached the banks on that topic. One banker was kind enough to show me the copy saying "it is part of our training."
BTW2: I'm not saying NOT to try it. I'm just giving you the heads-up as knowledge is power..