1) you definitely need more light
2) you seem to be overwatering
3) a seedling doesn't need to be transplanted that small wait for at least a few sets of leaves
4) when they are that stretchy you can bury the stem a ways
5) Whats your enviro like? Seedlings like a decent soil temp and humidity
6) you definitely need more light
7) You definitely need more light.
You should only water seedlings like that with a couple ounces of water every 2 to 3 days.
Whatever light you are using it is stretching a lot. You need more.