No, not in most countries in the EU and UK. But the license the casino uses can have its own restrictions in offering online gambling to certain countries. So, if you experience an IP block when visiting the website, it's probably because you are in a country that the casino can not offer their services too.
Every casino you find at slottomat.com follows strict rules regarding customer safety, gambling selection, and, not least, fair terms for its members. Although there might be foreign owners on some online casinos, they have licenses with rules and regulations they need to follow to offer online gaming to UK and EU players.
Most countries have their own law about paying taxes on casino winnings. If you are not sure of percentage or limits on tax deduction on winnings, please ask your local tax authorities.
If we are talking about amounts around 4- 5000€, Neteller and Skrill could be a fast and easy solution for you. Usually, the money is in your online account within 24 hours, and you can also have a very own card connected to your Skrill or Neteller account.