Answer: I think your plants are just about the right size for their age. Keeping the fluorescent lights one inch above the tops of the seedlings is right; be sure to use one warm white and one cool light fluorescent bulb to provide the full spectrum of UV rays. Also, be sure to keep the lights on 14-16 hours each day. The two plants that have fallen over may have the beginnings of a fungal disease called damping off. Check to see if the stems are discolored at the soil level. You can avoid fungal problems if you train a small fan on the tray of seedlings. An oscillating fan works well.
Leggy, or spindly stems are usually very apparent; they're thin, lack a normal healthy green color, and they tend to lean towards the light source. If your seedlings are growing straight up toward the light source, they should be getting enough light.
Hope this answers all your questions. Good luck with your broccoli!
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