I am still relatively new to the Yorkie world - Peanut is just 5 months old - and I too had heard some of the "horror" stories about Yorkies. I am sure that it varies from dog to dog and depends some on genetics, but my little Peanut is the best! He does nip and chew, but I think that is common for all puppies. Plus Peanut is teething right now, so the chewing on fingers has intensified some. As far as furniture chewing, you can buy something called "bitter apple" or an equivalent that has a bitter taste when sprayed on furniture, walls, electrical cords, etc. It has really worked with Peanut - one application on his favorite corner of the couch and favorite wall corner stopped that for good! Also, when Peanut chews on something he's not allowed to, I give him a firm "NO" and give him a toy to chew on. Once he is chewing on that I make sure to praise him - and it seems to be working pretty well. Housetraining has been going well, with a few days where he just seems to "forget". We started with wee-wee pads all over the place, then cut them back to just at exit locations, and now we have none at all. Peanut goes to the door and barks when he needs to go out (although he has learned to do that if he just wants to play outside, too! I am still trying to decipher the two!). As far as barking goes, he does bark occasionally but usually just when he needs to go out or if he sees a squirrel running by outside.
As long as you are sure you are ready for a puppy of any kind, I highly recommend Yorkies. I love my little Peanut and getting him was one of the best and most rewarding things I have ever done! He is very loyal, loves to play, is friendly toward guests, and is SO CUTE!
Good luck with your new puppy and I hope you get a Yorkie!