1) I meant, everywhere, depends of the type of star, gas giant, nebula and other astronomic oddities you are passing by.
(and also where you touch down on a planetary surface)
2) No issue with customizations, optimizations and upgrades.
It is possible to outfit a A10 to engage an air to air combat but it will never be as good as an F16.
The F16 is also design to perform precision air to ground strike. But it is sometime more advisable to engage tanks with an A10.
Customization, optimization and upgrades are fine to get the best possible result for your ship to adapt and overcome a hostile environment and dangerous situation.
But it has to come with a cost and drawback to match a role, a task, in order to achieve a specific goal.
Otherwise it is like saying, I want a B52 to be as good as a F15 to achieve air superiority.
This is where I am coming from and I know Elite Dangerous is more or less different on that matter, so again, it is just an opinion.
I have no argument with this at all. If you want the best ship for the job, by all means! If you want to pick something less efficient and give it a go, why not!