1, I always wore a 3 mil, if you are going thru a swim thru a skin isn’t any protection and once we got caught on the boat in a hail storm
2, Either way but if you have an analyzer be prepared to share it
3, I always have mine in carry on, not checked
4, Never been asked to see my log but you will be asked when the last dive was. If it’s been awhile they may put you on the newbies boat. The 1st dive site is usually trashed as they are watching your skill set before they put you someplace you could do damage.
6, Most resorts use purified water to make ice but in town I wouldn’t
7, Enjoy!