I presently own both a very nice Speed Graphic and a Crown and while I like them both, the Crown gets used about a hundred times more than the speed. In fact, the Crown is easily my most often used, non 35mm camera. I only shoot the Crown Graphic hand held. If I want/need to a tripod, or movements I'll haul out a more appropriate camera for that activity. Yes, you can accomplish most movements with a crown or speed but, it is a hassle and just not fun. If you want to shoot hand held, get a Crown or Speed - it really doesn't matter which they're both great. If you want to use movements get something else and forget about hand held.
- hand-holdable 4x5 environmental portraiture and documentary, industrial, landscape... etc.
The crown and speed were designed for hand help work. It is how these cameras were meant to be used. They excel at it. I can and very very often do hand hold the crown at 1/50th of a second shutter speed. No problem There are several examples in my flickr stream follow link in signature).
- I don't really need many movements. I would like some tilt and or swing though to create a dreamy look.
Movements? Dreamy look? Forget that gimmicky shit. If your shooting hand held, just focus and shoot. Documentary, environmental portraiture...these are not "dreamy".
- I'm not going to be using a flash.
Me either - cannot afford flash bubs.

But the flash handle is very...well, handy.
- Basically I want a 4x5 point and shoot rangefinder.
Get a crown graphic with a well adjusted rangefinder and be happy.
- I have a Fujinon W 135/5.6 lens. Could I get a graphic and use this lens on it? Advantages? disadvantages?
Yeah, you could...I guess...but, I see no real advantage. The stock optar and Xenar are fantastic. The 127mm Kodak Ektar is even better!
- Do either cameras have a revolving back?
No...There is no need for a revolving back. Does your 35mm SLR have a revolving back? Hand held...you wanna shoot portrait, hold the camera on its side!
- Which camera or model has the best rangefinder?
They have the same rangefinder.
- Which one is more suitable for hand-held photography?
I give a slight edge to the Crown - not only because it is lighter but because they are simpler. Shooting hand held is all about being ready and acting fast. The focal plane shutter adds complexity that can slow you down - especially while you're learning. It is one more thing that you have to think about - or can be. Starting out you do not need this added complexity.
- Would there be advantages to having a focal plane shutter?
You can shoot with any old lens you find laying on the side walk. Just hot melt glue it to an scrap of card stock of appropriate dimensions and you're good to go (sounds like I'm kidding. I am not - I've done this with ratty old enlarger lenses that I bought five for ten bucks - and gotten surprisingly good results).