USA, Canada / I have a Canadian and Polish passport. Travel on Polish / Canadian passport in Europe? [10]

Hello everyone, I am new to this site, but was just wondering if anyone has any advice regarding my travel situation.

I live in Canada and I have a canadian and polish passport.
I will be leaving for europe next week, leaving out of Florida, I will be going to Italy first and then driving to poland, arriving about 2 weeks after getting to Italy.

I will be staying until November (so exceeding the 90 days allowed on Canadian visa)
After my stay in Poland (with family) and traveling the rest of europe I wll be heading to Italy or barcelona and going home from either of those locations.

I will however be going home to Canada through the US again (florida).
My question is, how can I travel around europe on my polish passport (as to be allowed a stay exceeding 90 days) and then to also use my Canadian passport to leave out of barcelona so that I can get into the US. As I understand it I cannot enter US on polihs passport, so the only way I can get into US is by getting there on canadian passport.

Will I be permitted to travel around Europe on my polish pass port and then for the purposes of returning home to Canada via the US, will I be able to use my Canadian passport when leaving out of barcelona to allow entry to the US.

Just to clarify, I will be leaving and returning via Miami because I am taking a transatlantic cruise both ways.

ANyone know if I will encounter any problems, and if so how can they be remedied?

Can I apply for a US visa while im in poland in order to be allowed entry upon my return.

Or instead apply for a schengen visa while in poland (if that is even possible) to extend my stay to more than 90 days and jsut travel around using my canadian passport and then I will be allowed to enter US upon my return.

Any help would be greatly appreciated, thanks in advance...great forum btw