FFOF can be a little strong for seedlings. Do you have a pH and TDS or EC pens? Are you using tap water? If so, do you know the pH?
A lot of people who use FFOF put a few handfuls of a little bit weaker soil in the area of the pot where they’re planting. Something like Light Warrior seed starter mix, or even FFHF is good. I prefer starting in solo cups with a weaker mix, and then transplanting to a final pot.
The plant in the top pic doesn’t look too bad, definitely worth keeping. The bottom pic, it depends how the new growth shoots appear. Give her a few days. Sometimes they stay deformed and you have to chuck them, but sometimes the new growth comes in normal and they do fine.