1) I sleep irregularly, 5-10 hours. I nap any time I can. I think my sleep habits or lack of are from 13 years of child rearing (and a decade before that of being a student and not having a routine). I currently do not have babies, but my patterns are still like a young mother with disrupted and confused sleep.
2) Ideally I find I sleep naturally in 3-4 hour blocks and wake between these blocks. So a 7-8 hour sleep with an occasional nap or day to sleep in is perfect.