4. On flights other than to/from the US/
UK, you probably will have no issues with liquids, but check with the country to be sure.
Another note on international travel is that the time change can throw you off. If you take a long acting insulin, and travel 5-6 hours east, watch out for an overlap the evening after arrival, as it is less than 24 hours. Additional coverage may be needed when you travel west, and you may get an extra meal to contend with.