First go smoke a bowl and calm down, the worst things I've done is to get anxious and want to help, but then just end up driving the final nail.
Don't worry about being exact with the ph, it's a range 5.6 -60 for clones seedlings, 5.8-6.3 for veg and flower. You just have to be consistent don't feed 5.6 one day and then 8.0 the next they will be pissed.
Humidity domes importance depends on your environment, is it really dry where they are? is the light intensity high (shock), Too much air movement will dry them out. They just help keep a stable environment but again another aspect that can damage if not tended too.
A transplant already? people usually pop beans in water then plant directly into their cups?
They can tend to lean, and will stretch towards a strong light source (what your's looks like it's doing), but they don't need very much light at that stage, a 60 watt light bulb would be plenty. They don't have hardly any roots right now, they're trying to orient themselves toward the light before they start strengthening their stems.
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This is a seedling that has 3 sets of true leaves and has just started a feeding schedule (1 to 1.5 months old). The seed was planted directly into that pot of coco, still has a month before it will be transplanted to a 5 gal cloth pot.