Here goes the basic advises from me ...
1 : I would advise you not to visit Rostock and Magdeburg because those cities has A LOT of nazi skinheads who will be willing to beat the shit out of punks... and there are alot of nazis in rural parts of Germany.
2 : For hitching use hitchwiki.org because its quite hard to get out of towns such as berlin/dortmund/duisburg/essen.
3 : You can buy happy weekend train ticket for 5 people for 37euro and you will be able to ride all RE (Regional express) and RB (Regional Bahn[train]) across country free of charge for friday/saturday/sunday...
4 : As for getting into other countries... you can hitchhike ofcourse or use
http://hitchhikers.org http://rideshare.de or ride trains without tickets, it works pretty well, you get kicked off without a fine most of the time. Avoid ICE, EC, IC trains.. if you choose to ride trains and want to keep a low profile (avoid expresses etc...) here is what you do. This will be info for local trains...
a) Getting into Netherlands get to Duisburg, take a train to Venlo and you are in Netherlands, did this for like 10 times, never got fined.
b) Getting into Belgium, get to Aachen, take a train to Liege (this can be risky, got kicked off several times )
c) Getting into France, get to Saarbrucken take a train to Metz (You will get kicked off 75% as its only 2 car train )
d) Getting into Austria, get to Munich take a train to Insbruck (It can be a pain in the ass and you will get kicked out of the train 75%)
e) Getting into Italy, take EC train from Munich to Mestre (We rode in toilet for hours...got kicked out several times, but never fined)
f) There is no local line to Poland, only ICE express Berlin > Warszawa you'll get fucked up 100% in this train ... all my friends were fined, i personally never tried this one.
5 : If you have a bit more money you can fly with
http://ryanair.com http://easyjet.com they have pretty decent prices, you just have to book your flights like few weeks in advance.
6 : Shoplifting is a breeze everywhere, me and my friends never spend a cent in Germany ... go for LIDL, ALDI , Plus , Cento, Penny Markt chains its a 100% you wont get caught type shops, they just dont care.
7 : For gigs, meetings, squat actions use
http://radar.squat.net www.squat.net or
www.punx.nl (its a dutch punk site but it lists German gigs also).
8 : It will be pretty chilly in March so take some warm clothes with you.
9 : For free food (if you are not a shoplifter type) go to train stations (Bahnhof) in bigger towns there are Bahnhoffmissionaires( Free breakfast, shower etc..)
10 : Visit Kopi squat in Berlin, they might let you crash in there for a while...
11 : If you want some more information on something just ask...
If you want to visit Amsterdam i can hook you up with some people i know, because in March ill go to England, atleast those are my plans...