It's debatable whether that's an accent or a slightly funny way of speaking. He's extremely soft spoken in that interview, like using conditionals to soften his statements. Maybe he was just nervous. He's also speaking quite formally, like a newsreader would, using fairly few contractions.
Using Finnish swear words is quite common in Swedish speaking Finns. Finnish expletives particularly sound stronger (probably due to the harder consonants): Perkele!, Saatana, Vittu!
That's entirely false. A lot of Fenno-Swedes do not speak Finnish well. And virtually no Finn speak Swedish. They all loathe it because they are forced to learn it at school. Adult Finns can at most say a few canned sentences in Swedish.
I have never heard someone say "I am bilingual" when what they meant is "I studied another language in school and can somehow understand a few sentences". To me, and I believe, to most people, being bilingual means speaking two languages fluently.
You can get by with just Swedish if you live in a city or town where a large percentage of the population are native Swedish speakers. In Ekenäs, for example, around 80% of the population have Swedish as their native language.
Along the coast of southern and western Finland there are many bilingual Swedish/Finnish municipalities where most of the native Swedish speaking population lives. And on the island of Åland the overwhelming majority of the population are native Swedish speakers.
On the other hand in Central and Eastern Finland you aren’t going to get by with just Swedish.
perkeleen vittupää! I need to use this the next time our junior wants to merge something copy pasted from an LLM that not only breaks something but doesn't even do what it's suposed to do.