What you've got is correct, except you could add one thing to the first point...
You said sister chromatids exchange genetic material, which is true, and this happens in second meiosis division, or meiosis 2. However this also happens during the first division of meiosis, between the pairs of chromsomes in bivalents.
You could add as another point...
3. Random fusion of gametes: Since during sexual reproduction only 2 random gametes fuse to produce an offspring, this creates unique combination of alleles.
You said sister chromatids exchange genetic material, which is true, and this happens in second meiosis division, or meiosis 2. However this also happens during the first division of meiosis, between the pairs of chromsomes in bivalents.
You could add as another point...
3. Random fusion of gametes: Since during sexual reproduction only 2 random gametes fuse to produce an offspring, this creates unique combination of alleles.