A couple of questions I've been asked:
Difficulty of the Program/Will I be kicked out of the program?/What if they figure out that I'm not always the perfect person I tried to make myself out as on my application?:
The party line is that no one gets asked to leave Berkeley that wants to stay. I think this is more or less true. There is no exam which you have to pass the first time or you are expelled. The first year classes are hard, and very time-consuming, however all but a handful of students pass them, and those that don't have an opportunity to repeat them in the second year. The only tests that are really hard are the field exams in the theoretical areas. For example, econometric theory is known as a very hard exam. People often have to take additional field classes in the third year, because they didn't pass one of the hard field exams after the second year. The pattern here is that you always get a second chance, and most people make it on the first try anyway. Berkeley's philosophy (IMO) is to let you make what you will of your time here.
Funding:
(Again, as far as I know,) everyone gets funded after the first year. Some people get funded for the first year, a few some funded unconditionally for all the years, but most people have to take loans in the first year, and then teach or work as a research assistant to get funding after that. There are some fellowships floating around, but you generally don't have a chance to apply for these until after the second year, so they shouldn't factor into your decision as to where to attend. Also, the university gives you access to loans that are barely enough to get by in the first year, but then are very generous afterwards, when you take into account the stipend and tuition credit you get for teaching.
There is no need to worry that you will be competing against your classmates for funding or research opportunities; Berkeley economics feels more like a team than a shark tank. My only caveat is that if you don't speak English very well, you may have difficulty passing the exam required to get a teaching position. This means you end up doing less desirable work, like grading. I would strongly advise anyone who didn't learn English in grade school to work on it over the summer, for many reasons beyond this.
Summer Break:
Yes, we get summer break off. And, after the second year, we get the rest of the year off, too! (Assuming you can find funding , do your research wherever it is you want to go, and meet some minimum requirements the school lays out.) Summer after the first year is totally free; after the second year you generally spend the summer in Berkeley studying for the field exam- and enjoying the best time of the year in Northern California!
One problem, which I am not an expert on is that you must establish residency during your first year. This means you may need to stay in California after your first summer; more precisely, you won't be able to leave for longer than some length of time. I don't know very much about this- I've lived in CA since I was 12 years old- and I'm not sure how they would know if you were here or not... Anyway, it's worth asking about if you think you want to spend your first summer elsewhere. After you establish residency, you don't have to worry about this any longer.
If you are an admitted student and have any other questions, feel free to contact me. I would like to talk to you if you are applying next year, too, but I am very busy and probably won't respond to random emails with more than a line or two.