I don't use grow lights but put sowing pots and trays on windowsills or on a table close to the window. When the sprouts come up, I think you can remove the lid or at least keep a close eye so that you don't get mould. Tomatoes need to move to bigger pots after a while. I guess it depends on how warm it is outside but we usually replant tomatoes twice before they go into the beds outside. I've planted small (10 cm or so) tomatoes outside without repotting but they were very slow. I often get my tomato plants from my father and they have been repotted twice, which seems to be the right thing to do.
Regarding herbs, I suppose it depends on the temperature, but here cilantro works well sowing outdoors late spring and then sow anew every couple of weeks throughout summer. Dill also outdoors - wouldn't be possible to move the small plants!
Flowers I don't replant; when they are too big for their sowing pots, out they go, and hopefully it's warm enough outdoors.
