1 ) is there a way to save a render window in something else than 640 x 460 Ex: 1200 x 800 better resolution

2 ) When i transfert a file to look at it in VRML it seems fast
but limited in terms of rendering which is fine.

is there something in the near futur where there would be something equivalent as VRML1 in Blender - Kind of a viewer
Limited rendering but fast - Still able to see transparent and mirror things
An equivalent of VRML1

This could be an option for the render window - Have a choice bewtween a more complete rendering but slow and something where ounce rendered you can turn roll it relativement fast more like a 3D viewer

Instead of changing the camera in blender and then view the render window which is a slow process


About your first question:
You’re looking for SizeX and SizeY.