A2A: Yes. The IP addresses used by VPN servers are known. You could conceal your own IP by using a private proxy server. Can PokerStars detect VPN?

Yes, it is legal to use a VPN to play at PokerStars if online poker is allowed in your country. However, keep in mind that VPN usage doesn't make an illegal activity into a legal one. So, if you live in a region where gambling is extremely frowned upon, you might still get into trouble.