A guy who’s lived in the States for a decade and is married to an American is most likely very American in his ways. Hell, back in the '80’s Finland was called “the most American country in Europe”.
Painting with a broad brush, Finns take pride in individualism, moving own their own early compared to most other Europeans, taking pride in working from an early age and taking care of themselves from young adulthood into advanced old age. Speaking one’s mind and being honest and dependable are culturally valued traits. A common idea is that a Finn may be hard to get acquainted with, but once befriended, will be a great friend forever. Again, a Finn living in America may have very different ideas 
As everywhere else, it is common wisdom to abstain discussing politics and religion with anyone but one’s closest friends, if then. Most people are nominally (and apathetically) Lutheran, but atheism and secularism is totally ok. Politically, the numerous recognized parties and political agendas boil down to conservative and liberal sides, both with strong representation.
The “Nokia miracle” describes the huge IT explosion in Finland at the turn of the millennium. Tech industries were huge for more than a decade, with everyone knowing people working for Nokia, the number of millionaires rising etc. That has since dwindled, and Finland is a bit at a loss as to what to do next. Prior to the IT boon, forest industries, especially paper production, was a big, succesful industry. But paper too, isn’t selling all that well nowadays.
Finns consume loads of American culture, especially music, TV and movies. Subtitling everything means every Finn has, since early childhood, heard Americans speak, and the same hit shows and movies are invariably shown there.
Metal music is big in Finland, bigger and more commonly accepted than anywhere else. Still, many people never listen to the stuff. The most popular Finnish artists, by sales, are pop rappers and old-timey dance music performers. But contemporary, global Euro-American fare goes strong.
Traditional Finnish foods are rarely eaten nowadays, with pizza and burgers on most everyone’s favorite menu. McDonalds, Pizza Hut etc. etc. Chinese, Indian, Nepalese, Mexican etc. food is eaten with gusto in every bigger town. Reindeer is an expensive delicacy in most of Finland, while whales have never entered the Finnish waters or menus. Rye bread is the one truly Finnish thing that remains popular, but bread in general has taken a hit with the carb- and gluten-conscious trends. Rye bread and salmiakki (black salted licorice) are the two items that most Finns abroad dream about.
Ice hockey and soccer are the biggest sports in Finland, with lots of basketball, volleyball etc. too. Ski jumping is a near-national sport, as is the Olympic javelin throw, with International success for several generations now.
The question of who’s native is a bit tricky. The only acknowledged aboriginal people of Europe, the Saami, traditionally lived in northern Finland (and Northern Sweden, Norway, and Northwestern Russia). But the archaeological fact is that there have been various peoples in the area of Finland since the last Ice Age, and even Lapland was originally colonized by peoples unrelated to the present-day Saami. Finns haven’t come from anywhere, but have “always” been there, becoming Finnish-speaking Finns over the past 11 000 years, neighboring the similarly emerging Saami.