Also, did Karelia and Kola have any important resources or any important things?
All I can think of is the lend/lease agreement between the west and the Soviets. How much of it was transported to the Soviets through Murmansk?
About 25% of the Lend Lease cargo came via the Arctic Convoys. most of it was received in Murmansk though Arkhangelsk also received cargo during the summer months. (Lend-Lease goods were also sent via the Pacific and the Trans-Siberian railway, and via Iran). While Murmansk didn't receive the most goods, it was closest point to the West, and the arctic route was by far the shortest.
Can't really say much about other resources of the area.