A good resource to investigate is "The Out-of-Sync Child" by Carol Stock Kranowitz. It's a fast, parent-friendly read describing sensory issues, which are common in gifted children. My oldest has sensory issues - she is a mix of sensory seeking and sensory avoidant. What you describe - a strong dislike of someone who somehow invades one's sensory "space," being loud, smearing paint all over oneself - is common with children who struggle with sensory issues.