I never start lettuce inside so I don't know about it. I always direct sow lettuce into the garden. Is this leaf of head lettuce? If it's leaf it should be all right.

The tomatoes will be all right. Put them in a deeper pot and sink the stem into the soil. Be sure to remove any leaves that would be under the soil first. The tomatoes grow will roots all along the stem and it will make them sturdier. The stem will thicken up now that they are getting enough light. Not every plant will do this and some plants will die if you do so unless you know you can don't try it with other plants

I do think you started them a little early. They will be flowering before you can plant them outside.