Life / Question: Illegal Aliens in Poland [17]

Hello,

I am writing a paper on Polish immigration law. I have run into a bit of a problem regarding the penalty of overstaying the 90 set limit for foreigners in Poland.

Let's say a foreigner has exceeded the minimum 90 day stay and has remained in Poland for several years and decides to leave Poland. This person has had their passport stamped on the date of their arrival into Poland by an immigration officer at the airport. What if this foreigner wants to leave Poland? Would he/she be stopped at the airport when showing their passport? If so what kind of penalty would they face?

Let's say this same foreigner learns that it is possible for him/her to become Polish based on the fact that his/her father's father was Polish and emigrated from Poland in 1910 to the US. If this foreigner can collect enough documentation proving that his/her grandfather came from Poland and did not renunciate his Polish citizenship while he was in the US, what are his/her chances of becoming a Polish citizen while being of an illegal status (since he/she has overstayed their 90day stay period and has been in Poland for several years)?

I appreciate any information regarding this seemingly rare situation which I can not find any information about on the internet. Thank you.

Sincerely,
Max