glad they finally figured that out. last I checked(which I didn't think was THAT long ago) they hadn't figured out a way to roll their material. to be honest, i'm not at all a fan of how that looks, but that's a personal choice for sure. i'd be scared to hear pricing on that though. when I looked into a BD screen last year I came to the conclusion it was still cheaper to buy the highest quality plasma on the market in the largest screen size available for bright room viewing. still, can't say I don't want one.
Will higher gain also help out with ambient light or just dim projectors? I've heard the Epson 5020 referred to as a "light cannon", so I'm guessing I wouldn't need a high gain, correct? I think the Black Diamond comes in 0.8, 1.4, and 2.7.
I don't have much personal experience with high gain screens as I've never thought I needed one. but generally speaking, the higher gain screens focus the light. it's retro reflective, meaning whatever light hits the screen from your eye level will be shown the most. ideally that means your projector is mounted near eye level(something that makes me cringe personally) and no other light source is. if all your lighting is overhead, then yeah, the screen will do a good job of not reflecting that light to your eyes. but all that sunlight coming in through the windows would likely be around eye level and would still wash out the picture.
I believe there's two ways to combat ambient light and improve bright room images. one is the use of a darker screen material, and the other is a high gain screen. the black diamond really addresses both of those, and that's likely why it works so well in that situation.
[*] For daytime viewing (which would be infrequent but not rare), If I get blinds that are meant for blocking light on four average size windows and use a projector screen that blocks most of the light coming from the large window, could I save myself the cost of buying a Black Diamond screen?
probably, but it's still up to you to decide what is 'good enough'. the BD will still be better, if it's worth the added cost is impossible for me to say. it also depends on what you want to watch. sports, cartoons, anything 'bright' should be fine with a HCHG screen. dark movies would not be so enjoyable though.
[*] If I need to get a special projector screen for the ambient light, should I stick with SI Black Diamond? Every now and then I see people mention Firehawk G3 for rooms with ambient light as well. Also, I've seen reviews that the Black Diamond might have poor viewing angles, but haven't validated that myself yet.
best bet is to get screen samples and see for yourself. there's typically more problems with high gain screens. more chance of seeing screen texture, sparklies, hotspotting. and there's a direct relationship between viewing angle and gain. the screens can not create more light, then only focus it. when light is more focused, the viewing angle decreases.
[*] I'm inclined to believe that if the large window causes a mild amount of backlighting around the edges of the projector screen, it won't be problematic. Is that a correct assumption?
light hitting the front of the screen is the biggest issue. if that light comes in, bounces off the ceiling/walls/furniture and reflects back to the screen it will be an issue. otherwise it should be a minor concern.
[*] Ceiling fans come down around 14" - 15". Do you think it'll look weird if the projector mount needs to come down below that (with one of those extension bars)? Do you think the air displacement of ceiling fans will cause distracting vibrations in a non-fixed screen?
look weird, maybe, maybe not. I think it's more a matter of how high from the floor it ends up, than how far from the ceiling it is. as long as it's out of reach it's fine. if you're really concerned just browse around the web for pictures. I can't possibly answer the second question as I have no idea what fans you have, how far they are from the screen, etc. hang a bedsheet where you want the screen, find out for yourself. just keep in mind a screen will be a bit heavier and quite a bit stiffer. but hey, if the sheet barely movies, then you know you'll be fine.
[*] I've read about painting walls a dark color for projector rooms. Is that dark blue color (above) a bonus for this room? I don't plan on repainting the room either way, but I'm curious.
not sure what you mean by 'bonus', but yes darker is better, especially if you're concerned about ambient light bouncing around.
[*] Are there other questions I should be asking? Any details I'm leaving out? Other options I should be considering?
there are plenty of options. I think you'd be best off making a list of 'needs', a list of 'wants' and a list of 'dealbreakers'. only when you know exactly what you need can the mess of possibilities get narrowed down.