Curling Cotyledons? 2 day old seedlings.

Don't worry, they'll recover. Just let them dry out a bit before watering again. At least you spotted the error yourself and thought about how to fix it, which is what matters! Once they've dried out a little, you can put the humidity dome back over the top to keep the RH up. Keep going, you're fine! :)

a questo livello di crescita la pianta ha bisogno di caldo e umido perche adesso quello che gli serve attraverso l'umidita' dell'aria le radici si stanno formando ma non sono ancora la via principale di nutrimento quindi se metti troppa acqua marciscono i gambi e la pianta muore quindi secondo me se tieni umido dentro la serretta sei apposto ribadisco tutto umido non bagnato fradcio

Your lighting is fine and yes they are a bit soggy so you're right to let them absorb the water they have on hand. Good job so far.

If you are still using the humidity dome and overwatering then those could be your 2 problems. I would recommend going ahead and transplanting. Let them get some fresh air and let that soil dry a bit but not all the way, that might damage your fragile roots. Once transplanted only water the center of the pot. I like to use a spray bottle to keep from drenching them

Nothing I would be concerned about, They are still green and eventually they die off anyway. Its the true leaves you want to keep an eye on. I see they are making a slight V shape which can mean your light is to close. Its not to extreme so I would do nothing and let them get used to the light intensity as 36" is a good starting distance. They don't look over saturated to me, But I would be transplanting them into a larger pot to allow the roots to grow out more. Happy Growing