Cities to live in? (USA)

One suggestion.  Check the demographics, crime rate. Living somewhere isn`t very good if you feel like a prisoner in your own area.

I agree with everything said. 

Look around some more. Lots of nice cities here in grest climates.

If you have the time when you come for a visit, don't restrict yourself to looking at only the cities. This is a BIG country. The Commonwealth of Massachusetts is slightly smaller than all of Belgium and Massachusetts is one of the smallest states in the country. You will find that the crime rate is usually much higher in the cities.

From the comments you make here about Brexit and Christians, you would probably find more people that think like you in a rural area. And there is a LOT of rural area. But there are disadvantages to rural living. For example, it takes me nearly an hour to make a trip to the grocery store and back home. You learn to do as much as you can when you go into town; like buying non-perishable food in bulk. I do it once a month. On the other hand, when you live in or near a city, everything you need is only minutes away. I prefer rural living.

Guns? Yes. There are many. The U.S. is known around the world for it's love of guns. I live in rural Pennsylvania and private citizens probably have more guns than the entire Belgian army. But we do not go out shooting everyone and everything in sight the way some of the media attempt to portray it. Good, law abiding citizens far outweigh the criminal element.

Your choice of cities to explore have one issue to consider. Being on the Atlantic Coast puts them in line for a direct hit from hurricanes. It doesn't happen every day but the potential is there for catastrophic weather events. All 3 of the cities you mentioned were hit hard in 2017. If you should choose one of them, you should educate yourself on how to be prepared for a hurricane and be ready to evacuate when the call comes to get out.

As you move away from the coast and towards the mountains the risk of a large snowstorm comes into the picture. In North West Pennsylvania and Western New York State near the Great Lakes,  the snow is being measured in feet right now. Buffalo NY and Erie Pa. have had close to 10' of snow this winter. Being on the East side of the mountains we have only had about 5 inches. Cold? Yeah. It's brutal out there. High today will be around 20°F and it's going down near 0°F tonight.

Like Doug said, the Pacific NW has a very moderate climate. There is also the potential for major earthquakes on the Pacific Coast. But that risk is much higher along the southern coast than it is on the northern coast.

No matter where you go there will be positives and negatives. You will have to weigh each side and decide what you are comfortable with and what you aren't.

And like Topdown said, if you can arrange your visit to coincide with Chordiestock or one of the other Chordie events, you could talk to people from all over the country.

Good luck in your search.

I live in The Commonwealth Of Massachusetts. The winters are rough. The big cities have a lot of crime. We do have the best accents in the whole U.S.  Ask anyone that has spoken to me.

Thanks everybody!

I know about Chesapeake, Norfolk, etc. I use to read the local news (eg : virginian pilot), I started my researches in 2013. ^^
I also pay attention about US politics and everything related to the USA. By the way, you can hear the same fact in Europe but completely transformed so it's completely different from the US medias.
So far, Va Beach is the location I like the most. I heard about flood in 2017, but it was locally and this kind of thing can happen everywhere.

I'm still in contact with my US family, most of them live in Columbus, OH. But it's obviously not a coastal city
None of them visited VA beach.

My oldest brother lives in Columbus.  It is a great place.  Ohio State University, A diverse ethnic scattering, pretty good job outlook from what I can tell.   
You have not mentioned your skills aside from your many languages.  That in its self will be impressive. you might want to look into jobs with companies that are multinational and promote your linguistic skills.  Hire on as a Translator maybe.

Cities as you have heard, are vast, and well honestly most of the EU can fit inside Texas alone LOLOL!  Now, I will give you a rundown on the states I have lived in as being military I have moved around a few times.  West Virginia (from birth till 15yrs old), Wild and wonderful it is.  Dense forest and beautiful land.  Draw back, not a lot of employment and Opioids are a large problem, as they are in many states these days.  North Carolina (16 -21), another huge state going east to west.  Divided into 3 regions. Coastal Plain, the Piedmont, and the Mountains.  I grew up the second half of my life in the mountains of NC.  Much like West Virginia, Asheville is the main attraction, lots of great schools for university level, Asheville has become very expensive to live in as has much of the mountains. 
The Piedmont includes Charlotte, Raleigh/Durham (also known as the medical triangle), and Winston Salem.  It has been too long to give you any good job outlooks but primary industry is banking and medical, and manufacturing.  There are many more however I don’t have any info on them.
Coastal:  I can not tell you a lot, but I did live in a big area called Wilmington NC.  I went to school there a bit for university, but I cannot give you much in the way of better information.
Florida.  So many options but south FL is very different lifestyle wise than North Florida, then you have ocean side and bay side.  N. Florida is pretty much Orlando to the GA border. Jacksonville is very military oriented as there are 3 bases there, there is industry but it’s also been a while since I lived there.  Jax (as it’s referred to) sorta is more like very south GA.  It’s very hard to explain, you kinda just have to be there and travel around to understand it.  South FL is very laid back usually conservative politically, Miami (never been there and a world unto its self LOL)
Now to Texas: it’s almost 50 / 50 politically, I advise staying away from Huston, just don’t like that area.  The San Antonio to Austin area is amazing. Full of rich history, German decent people (your Dutch may still come in handy) in the Hill country area. Lots of diversity everywhere.  You have the coast to the northern panhandle.
From there we go to the Pacific North West.  You can read about Seattle and the industry around there and Portland Oregon.  Lots of Tech, Aviation, and commerce.
So for a fairly  half descent skimming off the top of my head there you are, I hope this helps