Feasibility of Space Fighters (and possibly potential thesis)(remind me of this one)

We know those scenes from Star Wars or Halo where you chase down enemy ships and space planes with your very own plane right? Well, assuming that this happens in above the Karman line, or just wherever the atmosphere doesn’t greatly affect the space craft, maneuvering can be a bit tricky because you cannot just pull up and expect you to go up immediately. Simply, as you accelerate in space, you are only going forward but when you pull up, I guess about 90 degrees should be good, for whatever amount of velocity you have during wherever you are pointing before pulling up will add up to your vectors. Instead of going in a short simple 90* turn, you do something like a 45* real fast curve to oblivion by the time a standard aircraft managed a controlled 90* turn.

Probably to answer this, you know those Velocity Vectors they use today? That thing that looks like this: (yes I can just pull one from the Internet but I’m lazy)
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—O—

We can just use that but how can we decelera—

I think I just answered my questions but still I feel something so odd about this

So... I need sleeping pills cause I can’t sleep