Are Virtual Particles Uncaused?

Virtual particles are not particles. A particle (or antiparticle) is a special type of excitation or "wiggle" which has a life of its own - it can travel off quite happily. (Think of wiggling a slinky toy and watching the wiggle travel off).

Can virtual particles be observed?

Virtual particles are also viewed as excitations of the underlying fields, but appear only as forces, not as detectable particles. They are "temporary" in the sense that they appear in some calculations, but are not detected as single particles.

Do virtual particles violate causality?

Do virtual particles contradict relativity or causality? ... Therefore, the interaction can happen no matter how far the interacting particles are from each other. Quantum field theory is supposed to properly apply special relativity to quantum mechanics.