1. i know you have to get a visa to live and work in Poland longer than 90 days. In the US, the penalties are steep if you get married here with the wrong kind of visa. Is is the same in Poland?
No it's not anymore. Too many people get married just for visa/citizenship. At least I remember you have to be married for 3-5 years before you'll get citizenship.
But I guess it's worth to wait, Polish citizenship will make you free from working visas in whole Europe. ;)
I don't know about working visa.. I think it's easer to get it if you're married.
2. Does anyone know how much money a cook or chef can make in Warsaw?
Depend of the place. Try to look for it in good hotels and restaurants. There's hundreds of them in Warsaw. I think it's about 1500-4000 PLN.
If you want to teach English, you have to pass some teaching courses. Not everyone can teach it just like that. You better start looking for it in the US.. And you will get working visa faster. Try Callan method, you don't have to speak Polish there. ;) At least I know you can earn about 3000 PLN / month.
3. Are there good websites to start searching for an apartment, room, flat to rent while I'm there?
When I was looking for mine, I found few pretty good here: warszawa.gumtree.pl/
Try also here: