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.
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.
In principle, you should never use payment information belonging to another person. This may result in you being banned, or not being able to withdraw any winnings without the owner of either card or other payment methods you use, also verifying their identity.
There have been many attempts to master this game over centuries. One of the first was probably the Martingale strategy. This is based on doubling the stake for each lost spin so you always end up with a profit. But unfortunately, both bet- and table limits will put an end to this in a short time.
Here at Slottomat.com of course! Here you will find a large selection of well-known, and new casinos offering different bonuses and wagering requirements. So you can find the bonus that best suits you and your game.