Is it permissible to deal with usurious banks by depositing money in savings accounts or current accounts, to benefit from the pension system that operates with interest, and to participate in commercial insurance for homes and cars, due to the lack of Islamic alternatives in Northern Europe?

It is permissible to deal with banks only to the extent of need. A current account is less problematic than a savings account, which is considered an interest-based loan, except out of necessity or a significant need, and a current account suffices for that. Commercial insurance, which is based on uncertainty (gharar) and gambling, is not permissible to voluntarily participate in, but there is no sin in what one is compelled to do. As for the retirement system managed by the state or companies, if it is merely grants, there is no sin in benefiting from it for those who meet the eligibility conditions.