Limbo between Polish citizenship and EU passport for an American

Hello, all you helpful and beautiful people. I have a knotty problem I'd like some advice on.

I'm an American interested in studying and working in Poland, in the immediate future and for the long term. A few years ago I got my confirmation of Polish citizenship (Decyzja), but for various reasons (grad school, the euro crisis) didn't follow up with the Polish passport process. Fast forward to this year, I've resurrected my ambition to go to Poland, learn Polish, teach English, pursue further professional training. I manage to buy a cheap flight to Europe before prices spike in the summer, I begin to gather the documents I'll need to receive my Polish birth certificate in Warsaw so that I can apply for my passport, ... and I find out from the Polish consulate that I must submit my passport application in the US, in person, at their consulate, because it's the nearest one to my current permanent address.

My questions are:
1. How can I avoid the costs of time and money to come back to the US to submit the Polish passport application?
2. How might I establish a permanent address in Poland (so that I can submit the passport application in Poland, instead of the US)?
3. What rights/advantages do I have now as a Polish citizen, but without a PESEL number or EU passport? Am I permitted to stay in the EU for more than 90 days?

I'm fine with biding my time in Poland for a while (traveling and learning the language, pursuing more professional training), pending the permanent address that permits me to apply for the passport that allows me to get a job ... but will my time in the EU run out after just 90 days, despite my status as a "Polish citizen"?

Thanks in advance for your thoughtful advice.

1. It should be possible that you have your attorney (or a family member) sign a document (confirmed by a notary public) to have a legal authority to represent you. Then they can go to the consulate and submit the application in your name.

2. I think the easiest and fastest way would be for you to have a rent contract in Poland (to show you rent an apartment / home). Then, based on this contract, you could go to the nearest city hall and ask to assign you this temporary address. However, I'm not sure if it's going to be good enough to apply for passport from Poland, wait for legal experts to answer ;)

3. If you are legal citizen of Poland, you will get PESEL without problems. Polish passport = EU passport so it has big advantage to have one. With a Polish passport you can stay in any EU country as long as you like.