Re: How many days a week ?
Four days a week: seven hours of regular classes, three hours helping out with the older kids (which can be quite a workout in itself). This is the limit of what my dojo currently offers, but I think it's also a good level for me. If I train every day I get wiped out and hurt myself. Every other day is a lot better for me.
For a while I was doing half an hour at home every morning, but I had some knee problems and needed to take a break, and now it's hard to get the habit back. I do some weapons work at home probably 3 times a week.