A world with no carnivores

I have, what I hope to be, a fairly simple question. I am designing a planet where there are no carnivores.

Assumptions

1. The creatures would all be very complacent and would feed and live in very vulnerable positions, because they have never learned otherwise.
2. The creatures would mostly be brightly colored, because the pressure to attract a mate would be much stronger than the pressures to stay hidden.
3. For the same reason as the above point, mating rituals would become very elaborate.
4. Finally, the point I am most unsure of: The creatures would quickly acclimate to a newcomer to their area.

What I am looking for in an answer

1. Are my assumptions correct?
2. What would the impact be on the local plant life (assume earth flora). Could it sustain itself?
3. Could the population be controlled without predators to keep them in check?

posted about 8 years ago

unknown‭

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