My 2 past CMs:
CM1 - didn't charge for her holidays or time off (including when her DC were ill) but would pro-rata her holidays so that I paid all year round.
Charged for all of my days off.
Initially wanted to charge for bank holidays, but I pointed out that I moved to a Monday at HER request and wasn't willing to foot the bill for EVERY bank holiday when I only used her once a week - so we agreed a pro-rata rate, so I paid a 1/5th of the rate on bank holidays. (Something to think about if you have a lot of part time children)
Did charge full rate for when DS1 was at nursery, but as he had a funded place that was fine.
Meals included, nappies not included.
CM2 - didn't charge for her holidays, time off or bank holidays (but we never had any on our days anyway).
Charged for my days off, but was term time only so that only happened with illnesses.
Charged just over 1/2 the rate for DS2's hours at nursery, but as he was her only charge during the day (which is what she wanted) she was able to do her own things, but just stayed local for that time. Also did that for DS2's after school club.
Meals included, nappies not included.
With regards to charging for your time off, unless you set a limit on it (5 days sick, 4 weeks holiday) I really don't think it's fair and would flatly refuse to sign a contract that had no limit.
Bank holidays - as I said above, as a parent seemed highly unfair when I was only using 1 day a week.
As a parent I think in all honesty you should work out what you want as your pay rate, and then add on 4 weeks holiday, bank holidays, and maybe 5 days sick leave and then rework the hourly rate to include them. Set aside a separate bank account, and put a portion of that money away into the account to cover your holidays etc. Because if you pro-rata then depending on start/finish dates someone will always be out of pocket.