Paying taxes as a foreign student

hi y'all,

once again posting here feeling like I should be punished for being so out of it... but here goes, maybe you can help.

I'm American, I've been in Germany officially on a student visa. What I understand is they give me two years to learn German, and then I have to show that I have successfully entered into the university by the end of those two years... or else. I am also permitted to work 90 days or 180 half days per year. I'm right now a year and a half into those two years, passed the testDAF and ostensibly about to apply for the university in these days.

Anecdotal advice has told me that if I don't make over around 7,500 € a year I don't have to pay taxes. So, I never got a steuernummer or a steuerkarte. Over this year and a half I worked teaching English and some freelance translating (regularly) for a website. Both times I signed something saying taxes were my responsibility, and the employers never asked me for a steuernummer.
Now I don't know if I've screwed everything up -- do I need to get one and report my income before I get in trouble?

Other thing that's just happened is one of these jobs may want to hire me for a lot more hours and money -- which will coincide with my starting the university. I understand there's a limit on time I'm supposed to work as a student/foreign student, but is there some sort of limit on the amount of money I can make?
And hey, what DOES happen to you if work more than those 90 days, and how do they find out?
And hey hey, what would happen if I went into the Auslaenderbehoerde to renew my visa and said actually I don't want to go to the university anymore and tried to get a working visa? Would that just be CRAZY?

Thanks, that's a lot of questions but I've been up half the night chewing my nails about it, so what else but Toytown forum to help me get some sleep.

with regards to your question about how much (more) you could legally work and earn combined with your student-visa status: isn't there supposed to be a special office for foreign students at every university where they hopefully know the laws and regulations by heart in order to help cases like you? did you check at one of the Berlin universities if there is?

Appart from that there are certainly some TTners who can and will help you. good luck,

Cheerio

Regarding that (and only that):
The time and money limits for students mostly reflects to their official student status. If you earn more than 7664 Euro p.a. (and are caught), you will for example technically no longer be applicable for health insurance packages on student terms, which would typically triple your premium (if going to the usual terms for self-employed/voluntary membership). The same goes time-wise, technically you're only allowed 20 hours per week; except for 53 working days full-time p.a. which have to be during lecture-free time.