Help!

Hi everyone. We recently purchased a home in Southern California and
the lawn was in really bad shape. Next year we plan to tear up
everything and put in sprinklers and sod, but for now would like to
get rid of the dirt lot/weed farm look,

After removing an old tree that was tearing up the lawn and sidewalk I
tilled the area around where the tree was and removed all the roots,
aerated the rest of the lawn which looks like St. Augustine and tall
fescue, mowed it about down to the dirt, covered it all with topsoil
and seeded with Bonsai 2000 Dwarf Fescue. The seeds germinated right
on schedule and the lawn is starting to fill in nicely with a mix of
all three grasses, but I am having a few problems now.

First, because we started a bit too early (eager to get a lawn instead
of dirt) we really had to stay on the water to keep things from drying
up, but I think we over did it and probably should have tapered off a
little last week. Now I can see a few areas with a mold/fungus on the
ground. Not a lot, but it is there in a few spots. Will this cause a
problem or go away by itself if we get on a better watering schedule?
Should I treat it with something like Spectracide Immunox or will the
cause a problem for the young seedlings?

The real problem is two pesky weeds/plants that are trying to take
over. Here are some pictures of the %$#$%&# little things. Can anyone
tell me what these are and what I can do to get rid of them without
killing the St. Aug and new seedlings? The lawn is really starting to
fill in and it looks great except for these little devils. I used the
half bottle of Spectracide weed killer (garden hose spray bottle) that
I had on hand with mixed results. Here are the pics.

..http://www.sixstringz.com/lawn/1.jpg
At about day seven a thousand of these little buggers sprouted. I
don't know if they are little seedlings of the tree that used to be in
this yard, but they sure look like it. The Spectracide seemed to have
an effect on this one as the leaves on most have curled and it looks
like they will die off.

http://www.sixstringz.com/lawn/2.jpg
This is the real problem. Is this some kind of clover or what? In the
areas where this is present it is really going crazy and grows
overnight. At first the Spectracide seemed to wilt some of the leaves,
but not kill the plant. What is this and how can I get rid of it?

http://www.sixstringz.com/lawn/3.jpg


Thanks in advance for any helpful advice.

Patrick