I've been 365 days for two decades. The real issues are staying within the law. In particular, taxes and anti-money laundering. AML laws since 2001 require physical addresses for virtually any financial transaction. Luckily I got a credit card in 1999 that still serves. Comments on a couple of other questions:
- general status games with airlines and hotels…
I don't "play". It's a rube's game. I will trade a good might's sleep for points any day. Beyond that, almost all of my points were recycled by my employer for business travel, so the only potential benefit to me was the status bit.
- how to have real relationships while being a nomad
I was lucky. 25 years, my wife and I had a great relationship. We both traveled a lot. We treated every get-together as a honeymoon. We picked and chose our rendezvous where we could best enjoy the time.
- dealing with mail, visas, taxes, citizenship issues
I have had four mailboxes around the world in the hub cities of my preferred airline and most common business locations. Visas are "rolling"/continuing challenge. Fortunately, most of my work took me to or through capitol cities. Sometimes I have to use visa services. As appropriate, I will buy the long-term visa over the three-month (or whatever).
- doing all of the above on your own dime while being reasonable about the costs.
I'm lucky. I can(and usually do) eat from the grocery store/market every night and be content. 36 years of travel and I haven't gained a pound.
Overall, please count the number of times I mention being lucky.