First off, I'd have some sort of homebase if I was a "steelhead bum". But it wouldn't be in BC. I've heard about the taxes up there are quite expensive. I know alot of times I'll head into the shops and tell them (I'm an American) and I get knocked down the tax. But, I assume if you go in EVERYDAY they'll raise an eyebrow and hit you with the full tax. Kush or someone up in BC can possibly verify. Haven't fished up in BC for, my God, 10 years. So things may have changed.
Personally, I'd live on the Olympic Peninsula. I'd homebase somewhere near Allen if I planned to fish most of western WA or BC and Forks if I only planned to fish the OP and BC. Plus, property is much cheaper for my small cabin/trailer that's gonna sit while I'm gone most of the time.
I wouldn't be a vagrant though. I'd find a way to either sell my flies on the river, or sell to shops. That way I can tie in the off hours and fish the rest of the time. Heck, I'd even make a "fish with me" guide service. I'm going fishing, so you can pay a small fee to fish WITH me. Get deals on gear and boats thanks to guide license, then take guys with you who'll pay for your trip. I would put disclaimer "I'm not out to put you into fish, I'm offering free seats in my boat. "
"Good angling ethic is not a monopoly practiced just by fly fisherman" - Bill McMillan