1) Yup, they're serious about ut. Most times they won't measure or weigh it, but when they do they don't allow anything extra
2) That's enough time, checked bags or not..
4) On the long hauls you'll have the typical pasta/beef option, you can still ask for a vegetarian option before your flight
5) LAN doesn't sell any alcohol, it's free onboard. About the before 10 am rule, i'm not sure about long hauls being like that as well.