1. No cheating (except resetsim), strict schedule - changing household every Monday 6am, aging on for active household only, aging on for townies each first week of rotation, last day for trying for a baby is Thursday (so the baby is born before the end of the week and you get to name it right after it is born)
2. It dependes. I play families since birth to death. Sometimes there are sims who don't have any children, so they are either alone, or with a spouse, with or without pets.
3. My current legacy runs for about a year and three months. I am at gen 7.
4. I use all the towns. My families live everywhere. Newcrest is just a regular town like Willow Creek and others :)
5. I don't know if I understand this question properly so sorry if I answer to a completely different quiestion :D IMHO, if you figure out how to play rotationally properly for YOU, then there is no way going back to play "regularly". The only problem could be playing huge rotation and with a goal you want to achieve and you dont take notes. It dependes on your playstyle and rules if you set some.
6. My playstyle is rotational realistic legacy.