As people who are actively cruising, have been for several years and plan to continue, I cannot give advice on the subject, but here is how we handle it:
Drivers License and voter registration in the state we started from - Hawaii
Car registration - who needs to own a car while cruising? We rent one as needed.
Street address for USCG Boat Document, anything else that requires a street address and mail - UPS Store. We have first class mail only forwarded. The cost is minimal and we never get junk mail.
In the 21st century one must have email and phone service.
Cell phones: We use TracPhones. Cheap, disposable. Cost about $20 for each phone plus $150 a year for minutes for both (We don't talk much and never txt)
Going out on limb here, but we think if you feel you have to yak on the phone and txt while sailing between ports, you might as well stay home.
For email we have our own domain(s) supported by our web sites. So far, the web sites have generated sufficient revenue to pay for the domain registration and hosting, just barely. We have always been able to find free internet access where ever we have been. Free email is available from Google, Hotmail etc. and may be a better solution but we like the control we have with our arrangement through Network Solutions.
Taxes, use fees etc. on the boat - Keep moving
The question was
about cruising was it not?
If you are cruising, We think your boat should be documented. I don't mean to give advice here but being a documented vessel has saved us a lot of grief. In Hawaii, for example, documented vessels are exempt from state registration.
This is what works for us. It may or may not work for you.