I'd be much more concerned with both Sweden's as well as little Finland's treatment of its Saami (commonly known as 'Lapp') minority to the North than about the Karelian population in Western Russia!
I'd worry too about the treatment of Sami in Russia too. Finland's stance during WWII is a bit of a dodgy spot. I think they were fighting a different battle which got them aligned on the wrong side.
I have many Finnish acquaintances and all of them speak excellent Swedish
Are we back to talking about the moomins again?
My Finnish is rudimentary at best
A couple of swear-words is all I know. And the word for hedgehog might be "sili". At least that's how a very nice Finnish girl I used to know said it (roughly). No, she didn't say it roughly - she sounded very sweet!