If Tuvix was nothing, then why was he so afraid of his demise? Why did observe and adapt to use his gifts in unique ways? I don't think he was Tuvok and Neelix in a static noise, he became something else.
Stockholm syndrome - people sympathise with and even romanticise their captor. The mind is a funny thing.
Now imagine how confused Tuvok and Neelix are as they scream and shout from behind a strangers eyes and try to communicate different thoughts simultaneously. Tuvix was afraid because logic dictates there is a potential risk and emotion dictates a necessary response to that risk. Once again, two minds trying without any success to communicate through one voice. As for his skills, what were they other than yet another combination of the skills of Tuvok and Neelix?