Blender Navigation limitations?

Why do objects start to disappear when they are scaled very big?
Why does Blender stop zooming in and out at some point?
Why does blender stop going sideways when holding down Ctrl+MMB scrolling at some point?
Why does blender stop going up and down while holding down Shift+MMB scrolling at some point?

Is there a solution to all this?
If not then what should I do?

BTW, I am making a gigantic city.

Why do objects start to disappear when they are scaled very big?
Clipping distances in properties panel

Best not to have scenes very very big or very very small
Changing from perspective to orthographic view may help