what's with all the questions this year? really!
1. i'll arrive with my flight at 4pm, i will be able to get the train from hamburg hbf to itzehoe at 06.02 pm? (considering delay and the bus from the airport to the hbf)
bahn.de they even have it italian. show SOME initiative.
2. just to be sure, im 18 so no problem for me, but a friend of mine is 16. he need some kind of proxy?
this has been answered in other threads about 20 times, even rather recently. go look.
3. in italy we can drink without problems, in germany its the same? or maybe there is a legal age?
search the fucking web. try wikipedia. it takes a second. oh LOOK!
http://en.wikipedia.org/wiki/Legal_drinking_age
4. i've seen trains which stop in elmshorn (from hamburg hbf) and from there you have to change train to itzehoe. it would be a good choice or there are some contraindications?
well it takes you to itzehoe doesn't it? or wait for a direct train. it makes no difference.
PS. I'm sorry if I sound angry. but these questions are posed constantly. and the answers are quite frankly really fucking easy to find out for yourself.