I know it's possible without any permit,
If u're buying cash- yeah! If u're lookin to get a mortgage, like u mentioned- I don't think so.
Don't know your status but I don't think any bank would offer you a mortgage.
U need to be at least permanent res for a mortgage.
Interest rates now vary depending, mainly, on deposit raised from as low as 2,9% to as high as 5,2% ( It could be more
coz there are too many banks in Poland) With 20% deposit you are better off. With 10% it's still possible but your interest
rate will be very high till you reach the remaining 10% through your monthly installments.Then there are provisional charges which
they charge for the mortgage. Best deals are in PKO Bank Polskie and Bank Pekao but this is based on you getting a packaged deal
with at least 3 of their products- top of the list being a bank account with them.
Can I get benefits from the Polish government
On what bases?
I wonder how old you are. There is MDM but that is for young Poles and the money dwindles
quickly around this time every year.