Q1.
Are laws of reflection applicable to spherical mirrors also?
Answer
Yes — the laws of reflection are valid for all kinds of mirrors: plane, concave and convex. They are laws about a single ray meeting a surface, and a spherical mirror is made of exactly such surface points.
Why the results still look so different: what changes on a curved mirror is not the law but the normal. On a plane mirror the normal points the same way at every point, so a parallel beam stays parallel after reflection. On a spherical mirror the normal at each point lies along the line joining that point to the centre of the sphere, so it tilts a little more as you move outwards from the centre of the mirror. Each ray still turns through i = r about its own normal, but because those normals fan out, the reflected rays end up converging (concave) or diverging (convex).
Tip: this is the key idea of the whole chapter — same law, different normals. Keep it in mind and every result about spherical mirrors follows.