Will the clowns get attacked by my false siamese aglae eater?
No, they won't, but you will have to rehome them like platytudes said, but they will be fine until they get around 4".
They need more room than 30" - they're very active, and also ich prone. Like cories, they need to be in groups of more than 2 or 3. I wouldn't include them. Try zebra loaches instead.
+1 on zebras, but IME, yoyos look way better, and are more fun to watch. I would get 4. And the females get pregnant often, but the fry usually don't live. All loaches are ich prone.