Sounds like there's some state-to-state variation here, especially in the case of the left coast states. Here's what I know, personally, to be the case in Florida.
Our residence has been in Green Cove Springs (St. Brendan's Isle) since 2008. We filed our "Intent to Domicile" with the County Clerk in Clay County, FL. Florida issued driver licenses and the county issued voter registrations. This year, we had to renew the driver licenses (October, 2013) via the State of Florida website. The renewal processing asked about a physical address, and since we don't have one, I just hit "enter." The computer went off, did it's validity test, and reported that St. Brendan's Isle was a qualifying address. Got our renewal licenses in less than a week.
We requested Absentee Ballots in 2013 (maybe 2012; Florida was at the time being sued by the feds for pursuing having a picture ID to vote). That process was is done online. To logon to the system, you needed your name, address and voter registration number. The voter registration office does not use "411 Walnut St." for St. Brendan's Isle' physical street address; they use "#1 Clay County." I did not know that, so I had to call. "Oh yes, sir, let me explain. No problem." Armed with the correct address, logging on was easy. The County Voter Registration system queried me on our physical address, I answered with our St. Brendan's Isle address, and SBI passed the test just fine.
We have never had the issue (that I know of) with our credit union or investment account institutions, none themselves located in Florida.
Florida also does not have a state automobile inspection system. A citizen here does not have a "duty to retreat" if attacked, and can have firearms for self-protection in their homes and cars. It may well be that the Patriot Act imposes some regulations about all this, but implementation/enforcement appears to be at the state level. St. Brendan's Isle does qualify as a physical residence. The way Florida handles it doesn't seem all that onerous to me.
Hope this is useful.
Jim
Peg and Jim Healy aboard Sanctuary, currently at Charlotte Harbor, Punta Gorda, FL
http://gilwellbear.wordpress.com
Monk 36 Hull #132
MMSI #367042570
AGLCA #3767
MTOA #3436