1. Is Poland a good country to study in overall for academic outlooks?
Not really. Poland doesn't have so world-recognized universities as the North America has. It doesn't mean the level of education is low, but I think a Canadian diploma will be worth more.
2. If I stayed in Poland, would skills like being completely fluent in French and English, help for anything in terms of a job search in general?
They will do, but Polish is important in Poland, as it's quite a unified country, with no many foreigners. And it's not an easy language to learn.
3. How easy is it to sustain yourself as a student there?
Poland is a cheap country to live in - if you have money earned outside. Unfortunately, as you are from Canada, not from the EU, our public universities (which are virtually only ones that count here, forget about the private ones, diplomas of most of them are worthless even in Poland) will charge the whole tuition fee from you - which normally, in case of Polish citizens, is covered by the state and the university education is for us free of charge.
At my university (Lodz University of Technology) the tuition fee for the studens from outside of the EU is 4000 euro/year + 200 euro for the application. Pretty much (although there are always some foreign students who pay it).
About the cost of living, you can find it on the internet, but having the source of money in Canada it will definitly not be expensive for you. But if you want to earn money in the country where you study and spend them there, Germany would be effectively cheaper.
4. Except that Canada has higher standards of living, are there any reasons you can cite as for why I should not stay in Poland after university if I manage to land a land a job there?
I wouldn't choose Poland as a place for study on your place, for the reasons I have already mentioned. It doesn't mean that Poland is a bad country. If you come, either for the studies, or for purely touristic reasons, you will definitely be welcome :)
5. What are some reasons to convinve me to stay there that I wouldn't think about?
I don't really know...
6. How are the outlooks for entrepreneurship?
There is no much cooperation between the science and the industry, it's also a weakness of the Polish higher education system. Although it's beginning to change.
If you speak French as a mother tongue, it might be a good idea to check France. They have some much more recognized universities. And it's also in Europe. Not so far away from Poland.