1. Many folks breed as low as 1200g if the female looks in good condition. By the time she ovulates usually she will hit that 1500-1800g. However, first time breeders should probably shoot for the 1500g mark.
2. Males I would prefer to be 700g+, there are many cases of males dieing from overbreeding. You can still kill a 1200g+ male though if you dont know what your doing.
3. Some folks drop temps, others dont. You will have to find out what works for your animals.
4. Its better to go by ovulations, usually 45 days after ovy they will lay.
5. 50-65 days depending on heat and whether you cut or not.