Student Visa/Residence permit

Visas, Permits, Passports and Naturalization
1
I recently received a letter from Universität Zürich, saying I had been accepted into their M.S. program in genetics.

Apparently I need to show up in person by september 7th, and cannot postpone enrollment without starting the application process again.

So now I am in a bit of a scramble to get things together in time.

Regarding the Visa Application:

Do I have to give an exact date for arrival, and departure?

Can I just give a month & year?

Can I ask for a 2 year visa? what is the maximum length of time I can ask for on one visa?

I don't know when I will arrive, as I am just starting to try and find housing (which I hear is really hard).

Will not having a visa affect my ability to rent an apartment?

What about the Residency permit?

I'm worried I'm going to encounter a "chicken and egg" problem here, where I can't get a residence permit/apartment without the visa, and until I get those, I can't say when I will arrive....

2
I want to add to this question. When applying to visa, do you need to have flight tickets and present them with the application too? I heard it is needed, but I did not find it anywhere in the instructions for the application.