So, you can create fixed schedules to run any combination of zones. You can not create a single schedule to run multiple times a day, instead you have to create multiple schedules.
No but if you want accurate water usage estimates the you need a correct percipitation rate. If you don't want water runoff the you need reasonable soil type and accurate percipitation rate.
Fixed can be run on day of week (mon, tue .. Sun) or odd even days. There are some,scheduling enhancements in the works but I don't know what.
Yes, I think 8 or 16, can't remember. You can not select a schedule and manually run it...for now, the ability to do so is in the back log.
You can snooze the controller for number of days.
It sounds like you are just looking for a dumb timer connected to the net, rachio can do that well. I'll add a few more things., ou can attach a rain sensor, a flow meter and a master valve (and control a pump). There is ifttt integration which allows for some additional,automation, like a temperature trigger syringing, email alerts, triggering schedules off of google calendars and many more. I personally have one to disable my system for 24 hours if my rain sensor trips.