1. Is it traditional for Polish men to pay for literally everything? I mean, are Polish men that accomodating toward their partner?
I am sure that some modern, open-minded, and feminist people wouldn't agree, but the answer, I am afraid, is YES! Traditionally, as a man, you are expected to cover all restaurant bills, entry tickets etc from your pocket. Traditionally - woman is treated like a princess. This tradition is pretty weak and quite old-school in Poland, but still exist. IMPORTANT NOTE: This not include clothes, jewellery or other kind of gifts.
2. Does she appear to have traditional values or am I being used for something else? ...something she is not telling me.
If she is a person who cherished "traditional values", she wouldn't agree any sex before marriage. Well... Not so soon anyway. You know her better. Answer this question yourself.
3. Do Polish girls like American men?
Yes, I think that overall that Polish girls like Americans.
You have to understand that Poland is a monolith nation. More or less - everyone in Poland looks, speaks and behave the same way. We haven't got any significant minorities in Poland. That's why Polish girls tend to fell in love in a men who are different from what they know. Let me warn you that, although these feelings are genuine in most of the cases, some cultural differences may be hard to overcome in the long run.
This is the first Polish girl I have dated so please pardon my ignorance.
There is no reason to "pardon".
Let me give you some advice. Mark it - this is just my Polish gut-feeling and it may be entirely wrong, but my words for you is: RUN!
Run as fast and as far as you can from this girl.