Well, in fact, it is not a study, but work (wissenschaftliche Mitarbeiterin). You have to do some scientifical work in the field of your researches. For me it's theoretical physics (quantum mechanics in fractal systems). You can be absent at work. You can come to the office at 6.00 a.m. or at 9 or at 2 p.m., but they need results from you. If you stay at work every day 8-10 hours, but you have 0 results, of course, you will be kicked out. If you want to work at home - no problem. Vacation is 26 days (working days, not calendar) per year. Normally it is impossible to take such a long vacation because of students, conferences, projects etc... If you have classes with students, you are not able to be absent these days. You can be absent only because of ill. But at least u can take 1-2 free days during a month or so.
As for my work, yes, it is really difficult. Increadibly. Since, at our uni quantum mechanics was so-so (Oleynik is the best, but program of education was quite weak), I have to read a lot, to come to know, trying to refresh mathematics in my mind. Without math it's impossible, of course... Nobody uses MatLab here. They say, it is quite old and not so good, as Mathematica. So, I should study this program. Hope to do it quickly (already started performing simulations of dendrimers and Serpinsky fractals.. interested in Husimi cacti). Today I need to come to know more and more.
Another FAQ: what about your german? My course starts on Oct, 18th. But I am already not bad. Every day I talk to my friends in german, learn new words, write them into my copy-book, and re-read them more and more. It's the only way. Grammar is really difficult. I also ask my friends and then remember it somehow. Sometimes I can speak german 5-6 hours, but it makes me stressed, no relax-ion, thinking all the time about right position for verbs in my sentences and so... At the uni nobody demands german. But, of course, it would be better to use it instead of English, at least sometimes...
Finally today we go to Stuttgart. I hope to have a looooot of fun there together with my "love", his sister and other friends of mine.. We will go through Schwarzwald, so 200 km will seem so long (approx. 3-4 hours by car due to narrow roads in mountains). Hope to put some photos after the trip!