What a great topic! I absolutely love hitch hiking and would still do it even if I was super rich. It is such a great way to meet people and explore the true culture of a place. Also you get to see the good and bad of a country which I think is important to get an overall understanding. It also makes you think on your toes, become very streetwise and adapt to any situation. I have hitch hiked in so many countries now that I have lost count! A few years ago I hitched from UK to China with a folding bike - check out my pictures at the post below:viewtopic.php?f=30&t=22933
Generally I find much of Europe to be the same; however I find Poland, Bulgaria and Romania pretty good. Even with 2 guys hitching you will never wait more than 5 minutes for a lift in Romania (day or night). When you are in Germany just make sure you don't get stuck in those very quite sidings on the motorway as it can almost be impossible to get out. The only place I have had real problem hitching in Europe is Slovakia. I only managed 30 miles in 15 hours! Once I got into the countryside and closer to Hungary things picked up a bit. I think my speed record for hitching was from Stratford Upon Avon to near the Ukraine in 24 hours!
As for food I find it can be really difficult on the road if you are vegan. I think the worse place I have ever hitched for food was Kazakhstan, where I basically lived on bread and fruit. This is why I tend to couch surf every so often when I am on the road so that I can touch base and cook some proper food.
If you get a change I highly recommend doing some hitching in Africa. The people are so friendly and it is super easy to get lifts. I went to Nigeria, Togo, Benin last year and hitched extensively.