[tokyo12345]

I'm going to Tokyo for a month, and before I go I have a few questions;

1) Is 31,000¥ enough for 4 weeks food? I won't be eating at restaurants (except for sometimes lunch and breakfast where I've seen meals at mos burger etc. at about 290¥) and will mainly just be buying bento from department stores and making my own meals.

2)Is there a Tokyo version of the JR Pass? Like a month long all access pass to Tokyo railway lines for a month?

3)How can I reserve a seat on the Keisei Ueno skyliner from the internet? (The Narita <--> Ueno skyliner) I've looked on their website and cant find out how to reserve a seat...

4)Recommendations of must see places in Tokyo

Thanks.