Likely cultural blips.

What kind of lighting?

And how many hours per day?

Have you fertilized? If so, with what and how often?

They're under a 4' shop light with 40 watt cool lights, and the light is on 16 hours a day. I haven't fertilized them yet because I thought you were supposed to wait until they were a little bigger (these germinated around 4/23, so they're a little over 2 weeks old).

When I transplanted these to new pots, I gave away several to some friends. I found out today that theirs are still looking great, even though they haven't fertilized them. So I don't think it's the soil or the lack of fertilizer.

The closest thing I can find online to the bumpy part of the problem is oedema:
http://msucares.com/crops/comhort/tomatodisease/images/odema.jpg It doesn't look exactly the same, but maybe if the bottoms of their leaves were purplish... I don't think I've been watering these too much - when I noticed the problem, the soil was drier than usual. I think it's pretty humid in my apartment though, so maybe that's the problem? Still doesn't explain the leaves curling and older leaves going chlorotic though... :(

If it's oedema/edema,it's a cultural blip, but not necessarily excess watering. Edema follows a combo of moderate temperatures, fully moist soil, and relatively high humidity.

Further, the underside of the bumps would be slightly raised and, early on, somewhat glassy. Those cells later take on a corky look.

Edema isn't a problem but is just one of those things that happens.

The older chlorotic leaves means the plant needs nitrogen.

Even though a number of folks on these forums hold off with ferts for quite a while, you'll give seedlings the best start if you begin ferts at 1/2 strength when the seed leaves turn from vertical to horizontal.

Now the leaves are wilting and falling off from the bottom up. :(