Yeah they are, to varying degrees. Characters from one series often make a cameo in later books, and the events in each have some effect elsewhere (though not as big an effect as they should imo... hopefully that changes in the next couple of books).
The
Farseer,
Tawny Man and
Fitz & The Fool trilogies all follow Fitz, so they're essentially a continuous narrative. There are fairly big gaps between them, so a lot of stuff changes in the time in between. The first two are really good, and the first book of the third felt the same level of quality imo.
Liveships is set to the south of the Six Duchies, and there are only a small number of crossovers between the two. It's a brilliant series in its own right though, the setting is awesome, the characters and interrelationships are all really complex, and the plot is great. Since it's third-person with many viewpoints set in trading ports and tropical islands infested with pirates, it can be a bit of a jolt after reading Farseer and it's single first-person viewpoint set in a more northerly location!
The Rain Wilds Chronicles are set in (a small part of) the same place as
Liveships, but follow new characters. Didn't enjoy them as much to be honest, though they're still fairly decent.
Yup, though since it's broken down into separate stories it doesn't suffer from the major issues people seem to have with WoT (have never got around to reading them myself). Liveships has such a completely different tone that getting bored of the characters and setting isn't an issue - the real problem is that most people tend to love Fitz and the Six Duchies so much that they skip Liveships completely