How will anyone know in the first 3?
If you stop time, the only person who would know is the individual, unless it doesn't stop for him? So he can move to a new place when he starts it back up? Same with slowing down or speeding it up. It would be mostly his perceptions.
Unless he can do this in a field for an 'area'. Say he can speed up time for a plant to produce vegetables in a day instead of two months. Or slow down time to be able to step out of the way of bullets being shot at him. Or stop time on a dog running to attack, turning it into a statue.
These are things that can be observed and would be useful. But it also depends on how much manipulation he is able to achieve, for how useful it would be on a larger scale. This would mostly limit him to being a very cool magician.
move around the time stream etc.
This is where things get interesting. Being able to move at least 'astrally' to observe past and present and future. This has so many uses that a government would sequester him (if possible) as soon as possible. One thing would be can he bring anyone with him in his 'bubble' to view other times? Then the government would send someone with him to 'see' stuff. It might be to find lost treasure ships, find secrets from the past (solve crimes maybe) and most definitely try to help predict the future. (can he bring things like a camera to document things? This would likely be a huge bit of useful information.
When he goes back in the past and can't affect anything, then I also assume he can not be observed, since anyone seeing him would alter the time stream, (unless this glowing man is the reports for all kinds of alien and religious sightings)
The future of course would be the most difficult part. Is the future set in stone? Or can it flow down different paths? If it is set in stone, and what you see IS GOING TO HAPPEN do you necessarily want know? If it's not, can you see probabilities, depending on actions? While it would be nice to know that stock ABC123 is going to go through the roof and buy it, knowing that someone puts a bullet in your brain because they tried to rob you after you became rich, and you ARE going to do both!
On top of that, is the future set because it's been observed? Is merely observing it making it more likely or even impossible to change? In any case the man would be 'locked-up' for study and testing, and any government would do it's best to make sure he was happy and there voluntarily, since it should be fairly 'simple' for him to escape if he should so wish.
Now societies reaction would be, he's a good magician, or some kind of hoax. Some small set of people would believe he has special powers and come to treat him as some sort of messiah, and a religion would grow around him. The government would likely look into it, if they find his powers will try to secret him away with promises and plant the notion he was a very good fake.