I've seen variations in the same strain both in leaf and bud shape and size. For Sativa/Indica hybrids, I don't think you can make any assumptions about how the plant should look. Not familiar with Blue Dream though. I have grown Blueberry and saw a lot of variation between different...
Since you insisted on a dry weight estimate, we're all expecting you to post it! How tall is that plant? Maybe I'm assuming it's bigger than it is. If that plant is 4 feet tall and growing outdoors, I can't imagine you'd get less than 3oz unless that's some airy bud that's not going to fill...
The one time I screwed up curing (by jarring too early and letting the humidity stay in the 80s) the bud got a funky ammonia-type smell and I ended up having to compost the whole jar. "Hay" smell has never resulted in bad bud for me. It goes away and the weed smell comes back with proper time...
You can still get light burn/bleaching without heat burn. I wouldn't want my plants that close to the light. Just get some of the garden wire and gently bend it or look up super-cropping and go that route. I've done both. The first time I supercropped, I was freaked out too, but it works...
Old seeds can be very tough and require patience. If you have any more, I would scarify and soak in water in a dark place until they pop and show a tap root. Then transfer to your medium. If you get any that push up with the seed casing attached, don't be afraid to gently remove it.
If you "just planted them," take them out and drop them in some water and put them in a dark place. Then get your coco mix properly ph'd and add some calmag at 1/4 strength if it's new coco. How did you get your coco to 7/7.5? It's should be 5.8 ideally.
Mine always came out close to 7. I assumed that was true for everyone but I guess it's different for different systems and input water (as I just Googled this). I assumed since pure water is 7.0, RO water should be close. But since RO water is so pure, the slightest amount of an acid or base...
I would insulate the walls and the roof. You can buy that reflective bubble insulation and put it inside on the ceiling to reflect heat back from the roof or put a metal roof on: you can get corrugated metal at Home Depot cheap and it's reflective. You definitely want insulation under that...
CalMag, IMO. Not familiar with sunshine mix though. If you are just using RO water, you'll definitely need to supplement CalMag. Are you feeding anything at all?
Be careful with chlorine. If you don't dose it precisely, your plants will be ruined (assuming they aren't already). You could try just the tea first and see how that goes. Both times I got to the chlorine/tea stage, I was weeks away from the eventual total collapse.