100k EUR per person per bank is the deposit insurance level provided in the state where the third party bank, that is available via Raisin Bank, is operating. I.e. not CBI operated DSG insurance but rather insurance in the state that the bank operates.
I have used Raisin for a long time without issues. Several other threads on Raisin here. Some complaints from others especially with their lack of phone answering but they are reachable via email.