You can book first thing 7am. Timer starts at 9am. You can’t book another attraction until 11am or until you go on the ride you booked. Touring plans suggests booking an attraction for later, around 4:30pm, for the 7am booking. But wouldn’t it be better to book an earlier attraction, like around 10am so you can use it and book another one quicker?
Yes in theory, unless you are trying to get an LL for an attraction that may be sold out first thing in the morning with limited drops or during the day availability.
Absolutely, it just can be really hard, so better to grab one of the fast moving LL later in the day, than to get it at all. But for sure, a SDD or JC sometime between 9 and 11 is as good as it gets.