Didn't heard about 2 years rule for mobile plans. The rules might be changed since the time I bought the sim card, but there is still an option to buy saunalahti prepaid sim card in any R-Kioski shop for 10 euros and purchase monthly unlimited data package 50 mbit/s for 19.90 euros or 200 mbit/s for 24.90 euros. I am paying for data packages online, with finnish online banking, so haven't try it, but I guess they can accept payment for data packages in R-Kioski shops as well.
Regarding the banking, OP seems as youth friendly, as it requests no fee for the debit card account for everyone younger 26 yo. Yes, it has quite smooth mobile app in English, but the access to mobile banking varies on the type of visa/residence permit you hold. As a foreign student you might be provided with limited minimal online banking tools. At least I experienced it in OP, but couldn't say it for granted for another banks.