Excerpt Limits

I’m trying to do the following:

1) When I use the_excerpt for some reason pictures that are inserted do not show up… Can I change this to allow the pictures to come up?

2) Is there a way to change the excerpt limit? Either make the “excerpt” field on posts mandatory, or make it so that instead of the default limit of words showing up for the excerpt tag, a shorter amount of words? Is there a way to specify that?

I know about the <more> thing, but that would mean my users would have to use it in their posts, and I need something mandatory, or automated to avoid massive moderation.

Any ideas?

Eric