Cook the tomatoes on a grittle until cooked, peel the skin (should come off easily), then put in a blender, add a little water while blending.
Tomato puree
yes, but try and source a can without tomato seeds/pips in.
If we put tomato paste in mixer,its result would be puree.Therefore there is no difference between two. One can easily substitute each other.
you can but it will not taste the same.
yes