If you know someone that could travel time, how would that look like for you? Is age not an issue for them or rather since they have access to any information in time, they know which action would lead to the best result. Imagine if you could potentially alter what happens to a world, what would you do.
Most of the time travelers in movies and books tend to interact with people that does not share time travel capabilities. This is because certain interactions could potentially be harmful for people or there could be things that are missed or just completely left undiscovered or ignored. Think Marty Mcfly in Back to the Future, the possibility of erasing yourself because your dad missed the opportunity to get to know your mom. Now imagine time traveling is available for not just one person where they try to jump on top of each other thus creating a series of prevention of opportunities for one another. That is much like war at that point where chaos is the norm and all things are free for all, that is worse than any nightmare I could imagine.
Though what I mentioned above is the scary bit, there are a lot of things there are a lot of convenient things like getting to know which horse would win a race or if you need to cancel a meeting in case the other party is a no show. It seems to me that regulating might be a challenge, though I would assume they want to keep a low profile and limit the impact of their actions thus there is a self regulation that happens innately. If you had that capability, what would you do? Would you abuse it? or would you lay low and create a small opportunities instead.