First grow

Yes that seedling is likely overwatered. Somewhat obvious because of how the cotyledon leaves are clawed downwards, and you can see puffiness in its first ‘real’ leaves. It’s too much medium for such a small plant. Starting in a solo cup or rapid rooter cube will be more reliable and help with overwatering because smaller medium dries out faster.

no, they just look small and thats to be expected for a seedling. dampening off causes the base of the seeds stem/truck to shrivel up and collapse under its own weight. I do not see any of that happening here, Good Luck!

Hi, Loos like they need more humidity. Put them under a dome or transparent cup and keep it moist underneaf. Seedlings don't have many roots an can't take up too much water so they need to stay under higher humidity. They consume most of their water over the leafs they got. Hope this helps.