1. Are there any other transformations besides reflection, rotation, translation and enlargement?
Yes, shear is another transformation.
2. Are there any invariant points under a translation?
No, all points move.
3. What happens when an enlargement has a scale factor of 1?
Not much! The image will be the same size as the object and in the same place.
4. What happens when an enlargement has a scale factor of -1?
A bit more! The image will be the same size as the object but on the opposite side of, and the same distance from, the centre of enlargement.