If you want a nice salary and cold weather, go to the Scandinavian Peninsula countries.
If you want a moderate salary and warm weather, go to the south of Europe. (Portugal, Spain, Italy)
The rule is this: The more north you go in Europe, the more expensive things get. South is the cheapest.
The amount of English speakers is higher in Northern Europe. But you will likely find them in all countries here.
Edit:
Also, this is both personal opinion as the one of others to whom I've spoken with. Ppl from the north of Europe are a bit more cold and seems to be harder for them to be friendlier than the ones from the south.
Costs:
Food is equivalent price thought it does raise a bit north, and lowers south.
Housing price it's 2 subjective it depends on where you're going to, if it's a country capital, etc...
I can give my personal experience on it. In Portugal, Coimbra my city a room costs you arround 150€ and a house will cost from 400€ a T0 to 1000€ a T2/T3.
In Sweden where i am now it costs a room 350€ (4000SEK), and house will cost around 2000€ / 20000SEK I guess.
In Luxembourg my cousin pays For a small T2 in a city near the border with France 1900€ and in the Luxembourg Capital the same would go for arround 2500€
Unlike what I've heard about America (no offense here, it's what a friend living there told me). In most cities you can go around perfectly without a car as the EU countries invest a lot in public transports.
- Safety is no problem at all. It's also a bit subjective, but foreigners aren't bothered in most countries, so unless you go to the ghettos I guess you won't have much of a problem. For example here in Sweden (Goteborg) the amount of foreigners is so high, I hear more english than swedish
A visa is pretty easy to get. So I wouldn't see much of a problem there.
Visa allows you to go to any European Union country. With some limitations on the amount of time you need to be there, but you only need to take one visa for all EU (except UK, see shengan space for more info on that)
After you land here, just use ryanair is much cheaper to travel. Goteborg -> London -> Porto costs me arround 130€ to go and come back included.